Yeah, it is a bummer about the nitros. We've thought about letting them sit outside for a while then bringing them back in and trying to only heat the engine block and head with a hair dryer, but we're always too lazy to try. We figure the outcome wouldn't be worth the work anyhow.
nitrosport, letting them get cold so the snow doesn't turn into water is another nice benefit that I forgot to mention. Usually, it's cold enough outside that the motors, ESC, and battery(for the most part) stay cool enough that they don't melt the snow either! I don't really worry about water though, I have my Rx's and ESC's waterproofed with liquid tape. I could drive my LB and Clod underwater and it wouldn't matter!

I only waterproof Rx's on my buggies and ST's, I basically only race those on my track when it's dry anyhow.