I'd suggest pulling up the Alcor website and digging through it. There's a lot of facts and research there that address most of this. The short answers: preserving bodies is dirt cheap, the thermodynamics mean that external temperatures are a trivial factor, and there's a fairly well done trust fund to support everything (IIRC, the investment required was based on a 2% annual return, and then they doubled it just to be on the safe side. Bankruptcy happened once, at the very dawn of the industry, and every current cryonics agency is very careful to avoid that happening again.)