Certainly New Jerusalem will have jewels, streets of gold, etc. But I don't believe the rest of the earth will be like that. I personally believe God created this earth prior to this age in all it's glory. That one was destroyed and we look forward to a new one. It's going to be the earth restored but I highly doubt it's all palaces, thrones, jewels, etc. I think it's most likely we will have our own lives, build our own houses,vineyards, all the while going to the New City to worship, etc. Especially going by these verses
Isaiah 65:17 "For, "Behold, I create new heavens and a new earth: and the former shall not be remembered, nor come into mind."
So anyone looking to hold onto the former, it won't even come to mind.
Isaiah 65:18 "But be ye glad and rejoice for ever in that which I create: for, behold, I create Jerusalem a rejoicing, and her people a joy."
There's going to be so much joy.
Isaiah 65:19 "And I will rejoice in Jerusalem, and joy in my people: and the voice of weeping shall be no more heard in her, nor the voice of crying.
Isaiah 65:21 "And they shall build houses, and inhabit them; and they shall plant vineyards, and eat the fruit of them."
And you brought up a personal note-
Isaiah 65:24 "And it shall come to pass, that before they call, I will answer; and while they are yet speaking, I will hear."
It's going to be amazing. I'm like you, I prefer simple things, etc
Mansion just means resting place and through Christ and I think we have that now. I don't think it means what most people believe. I'd be happy with just a little cottage, gardens and some animals roaming around freely.That's my ideal Heaven. But whatever it will be I trust our Father and once we are in our new bodies, I know we will love it. It's promised. Our Father's eternity is going to be unlike anything and all prepared for those who love him.
It's hard now because our human minds can't quite grasp what it will be like.