Jon probably could chime in here... but it's easier (and cheaper) to build from scratch, than to have to retrofit an existing space and tie into existing structure,electrical,plumbing, etc. So I wouldn't let that bathroom re-do scare you too much... although 50k is a lot of money, hopefully you have a spectacular bathroom. How much to build a whole house? I couldn't honestly tell you. In a normal world, a quarter million should cover it as long as you don't get a contractor trying to squeeze you dry, which as mentioned a few times probably would happen if they have a lot of work available. This is where it helps to have friends, family, etc who are knowledgeable in these areas, not that they'd work for free, but they probably would be less likely to ream you.
Housing, yeah $1500 better be amount they're throwing in for free, you can take a trip somewhere to live, or buy a really good tent for the backyard
I'd move in with my parents, but they're just a stones throw down peninsula, and might be in the same issue as me. It really would be time to consider that part of the deductible. Maybe send your family someplace nicer (parents) and stay at a sleezy apartment while you continue to work... *shrug*...
Hell all my equity is this house, this is my retirement, so its all on me if it comes down. I won't deny that its scary, especially considering where I live and a house right next to mine, and another next to that, but on the downhill side no house, I very easily could be pushed over by the other two houses
But like I said, a good tent, hopefully the solar panels are still working, and I can do some serious long term camping in the worst case