I don't really like your argument. How can a Christian not share the good news to the person whom he loves when he knows that separation from God is the result of those who have not committed their life to Christ Jesus. This shows me that the husband did not really love his wife. True Christianity is intolerant...it is the only way to life everlasting. The Bilbe promises us that " Believe in the Lord Jesus, and you will be saved- you and your household" Acts 16:31. God wants all to be saved. I do belive in the power of prayer, if the husband prayed all of his life for his wife to get to know the Lord...I do believe that his wife could have been saved. Besides that the Bible talks about people who are married to a unbeliver that if they live godly life and show true love, the outcome is the salvation of the unbelieving spouse. I have not yet known any person who is married to an unbeliever who live a true christian life that their spouse did get to know the Lord as a result. This is how my unbelieving dad got saved. Jesus said that if you only have a mustard seed kind'a faith you can move moutains... how much more if you have mountain-size faith.
Another thing, when we get to heaven God don't give us a choice, the choice has been made here on earth. Your argument my friend in the Lord is only fictitious. God commanded us His children to teach all nations His everything He has taught us. It is our responsibility to share the gospel that people might be saved. If we don't do this we might get to heaven but suffer loss.
How can I enjoy heaven knowing that some of my family members and friends is not with me? Well, with logic I cannot really enjoy heaven. I have a relative who is in hell because I did not share the gospel to him when I had a chance. He commited suicide years ago. I deeply regret for not sharing the good news to him. One thing I know though that God promised that He will wipe away my tears. Everything will be swallowed up by the mercy of God through Jesus Christ. This present heaven and earth will be purge by God. We will live in a new heaven and a new earth. My friends all of our mistakes will be covered by the blood of Jesus Christ.
I don't have all the answers to this argument but one thing I know God loves me, and I have committted my entire life to Him that many people could know Him through my life. How I hope that every person would be there in heaven. Love ya all!