[The real answers are the slightly more depressing: he knows what it's like to be without a home and doesn't want to put other people in that situation by taking theirs, and he doesn't want to go back to his brother- who he knows would take him back in- because he wants Mako and Wu to focus on their life together and Bolin doesn't want to get in the way of that.

Which is what he really doesn't want to be forced into admitting. The last thing he wants Mako to take away here is that it's him having a relationship that is the problem. Because he knows Mako will read that and it isn't a rabbit hole Bolin wants to go down.

He knows Mako will take this as a personal failing either way, but he can at least try to guide them towards a softer landing.]

I wont freeze. And besides, I think I'm only going to be here another week. Maybe two, tops. Worst case, I'll get a hotel. I just want to find a home that isn't waiting for it's people to come back.