Ever consider bicycling? it's low impact, highly aerobic, easy on the joints, fun, and has some survival preparedness value, as well.

I encourage you to support your local bike shop. They can outfit you with a decent non-suspension mountain bike, a helmet, lights (it gets dark early now), frame pump, heavy duty lock and basic toolkit for < $800. Have them replace the knobby tires with decent road tires, and there ya' go. You can even get an "indoor trainer" for off season. Usually they clamp to the front fork in place of the tire, and have some sort of friction rollers for the back.

If the budget is running a little tight pre-Christmas and post-relocation, there's always Craig's List and police auctions. A set of panniers ("saddlebags" that go over the rear rack and tires) extend it's versatility into the survival, no-gas realm.

Why a "mountain bike" for the road? The riding posture if far more comfortable and less intimidating for new or older riders, and the bikes are a bit sturdier. The efficiency trade-off is minimal for most fitness and recreational riders, and replacing the off-road tires with good quality road tires recaptures much of that, while still allowing occasional riding on dirt roads or improved trails.

I consider most suspension systems to be mere marketing ploys on most lower end bikes for recreational riders. They are great for technical and aggressive off-road riding on better bikes, but they add unnecessary complexity and weight for most casual riders, and the cheap ones don't work that well. Also, they are NOT for improved rider comfort. Get a gel saddle and gloves for that.

You can pick up a spare set of used wheels and mount off-road tires on them for those occasions when you plan to do mostly trial riding. That works well for me.

I suggest considering buying a basic used mountain bike for survival purposes, anyway.

Jeff