You are correct that the 7 trumpets emerge from the 7th Seal. And yes, the bowls correspond to the trumpets - but, as I'll get to in a second, that is as far as that goes. The trumpets pertain to the faithful, the wrath for the unfaithful. There are time elements for the trumpets, but not the wrath.
As to the length of the 2nd woe, it does indeed say that the 6th Trumpet is
at least 1260 days.
Each woe is a trumpet. When the 1st woe ends (aka the 5th Trumpet), the 6th trumpet/ 2nd woe starts. The 2nd woe doesn't end until after the 2 witnesses are told to 'come up here'.
Rev 9
12 The first woe has passed; behold, two woes are still to come.
13 Then the sixth angel blew his trumpet, and I heard a voice from the four horns of the golden altar before God, 14 saying to the sixth angel who had the trumpet, “Release the four angels who are bound at the great river Euphrates.”
[...]
Rev 11
11 But after the three and a half days a breath of life from God entered them, and they stood up on their feet, and great fear fell on those who saw them. 12 Then they heard a loud voice from heaven saying to them, “Come up here!” And they went up to heaven in a cloud, and their enemies watched them. 13 And at that hour there was a great earthquake, and a tenth of the city fell. Seven thousand people were killed in the earthquake, and the rest were terrified and gave glory to the God of heaven.
14 The second woe has passed; behold, the third woe is soon to come.
Your notion of the 7 years of 7 seals doesn't really seem to hold up well to scrutiny imo. Here's why: Apollyon of the 5th trumpet is 'the antichrist', and I'll prove it. (Apollyon is the 'lawless one.')
Here's what's neat about the bowls of wrath: they have no time elements, which means they all occur simultaneously!
The 6th & 7th bowl of wrath is the event that is happening at the 6th Seal!
Rev 6
12 When he opened the sixth seal, I looked, and behold, there was a great earthquake, and the sun became black as sackcloth, the full moon became like blood, 13 and the stars of the sky fell to the earth as the fig tree sheds its winter fruit when shaken by a gale. 14 The sky vanished like a scroll that is being rolled up, and every mountain and island was removed from its place. 15 Then the kings of the earth and the great ones and the generals and the rich and the powerful, and everyone, slave and free, hid themselves in the caves and among the rocks of the mountains, 16 calling to the mountains and rocks, “Fall on us and hide us from the face of him who is seated on the throne, and from the wrath of the Lamb, 17 for the great day of their wrath has come, and who can stand?”
now jump forward to the 6th & 7th bowl of wrath
12 The sixth angel poured out his bowl on the great river Euphrates, and its water was dried up, to prepare the way for the kings from the east. 13 And I saw, coming out of the mouth of the dragon and out of the mouth of the beast and out of the mouth of the false prophet, three unclean spirits like frogs. 14 For they are demonic spirits, performing signs, who go abroad to the kings of the whole world, to assemble them for battle on the great day of God the Almighty. 15 (“Behold, I am coming like a thief! Blessed is the one who stays awake, keeping his garments on, that he may not go about naked and be seen exposed!”) 16 And they assembled them at the place that in Hebrew is called Armageddon.
The Seventh Bowl
17 The seventh angel poured out his bowl into the air, and a loud voice came out of the temple, from the throne, saying, “It is done!” 18 And there were flashes of lightning, rumblings, peals of thunder, and a great earthquake such as there had never been since man was on the earth, so great was that earthquake. 19 The great city was split into three parts, and the cities of the nations fell, and God remembered Babylon the great, to make her drain the cup of the wine of the fury of his wrath. 20 And every island fled away, and no mountains were to be found. 21 And great hailstones, about one hundred pounds each, fell from heaven on people; and they cursed God for the plague of the hail, because the plague was so severe.
Now go back to 2 Thess 2
3 Let no one deceive you in any way. For that day will not come, unless the rebellion comes first, and the man of lawlessness is revealed, the son of destruction, 4 who opposes and exalts himself against every so-called god or object of worship, so that he takes his seat in the temple of God, proclaiming himself to be God. 5 Do you not remember that when I was still with you I told you these things? 6 And you know what is restraining him now so that he may be revealed in his time. 7 For the mystery of lawlessness is already at work. Only he who now restrains it will do so until he is out of the way. 8 And then the lawless one will be revealed, whom the Lord Jesus will kill with the breath of his mouth and bring to nothing by the appearance of his coming.
9 The coming of the lawless one is by the activity of Satan with all power and false signs and wonders, 10 and with all wicked deception for those who are perishing, because they refused to love the truth and so be saved. 11 Therefore God sends them a strong delusion, so that they may believe what is false, 12 in order that all may be condemned who did not believe the truth but had pleasure in unrighteousness.
As you can see by the green highlight, in the 6th bowl is the 'coming of the lawless one'. The 'restrainer' of 2 Thess 2:6 is this ascending angel from Rev 7
After this I saw four angels standing at the four corners of the earth, holding back the four winds of the earth, that no wind might blow on earth or sea or against any tree. 2 Then I saw another angel ascending from the rising of the sun, with the seal of the living God, and he called with a loud voice to the four angels who had been given power to harm earth and sea, 3 saying, “Do not harm the earth or the sea or the trees, until we have sealed the servants of our God on their foreheads.” 4 And I heard the number of the sealed, 144,000, sealed from every tribe of the sons of Israel:
He is restraining the 4 angels from destroying. And also the angel that releases Apollyon in the 5th trumpet.
So, who is the great city of the 7th bowl that is split into 3? That is the woman that rules the world, that goes into the wilderness in Rev 12.