We weren't discussing all out survival mode really we were discussing how to be self sufficient going into a situation that could become an all out survival mode situation.

If you get to a place where you have to put chains on then you should know how to put them on yourself...if you pay someone else instead than fine do that, but know how to put them on regardless in case you get into a storm and have to because storms in the Sierras this time of year can and do come on fast and can and do leave people in very bad spots. If you can put chains on it may very well be what gets you out of a potentially dangerous situation and preventing an all out survival situation altogether by being self sufficient.

Extra jackets, blankets, food, road flares, water and maps should always be in your car during winter travel anyways when talking about remote locations such as the Sierras and the passes over them. It would be stupid and irresponsible not to prepare for a "just in case" scenario especially if unfamiliar with the area and weather.