I think it would be awesome if Bethesda made another "Hearthfire" addon where we build an entire wall city near Winterhold called, New Winterhold. I think it would be fun if our role was something like a foreman and we had to organize workers, acquire resources, negotiate shipments, etc. Then we'd need to hire guards and entice people to open shops, maybe secure roads, maybe appoint a Jarl. There's a lot that could be done.

i would love this,it's been pointed out that there's not enough land,but i think it could be worked in somehow

I've seen the same suggestion made with Helgen. Seems to be a common theme.

And before that, Kvatch.

There's a few mods out for Oblivion that rebuilds Kvatch, too.

Hmm... maybe gamesas will allow us to help rebuild cities destroyed during/just prior to the Main Quest of the next game?