One of our neighbors has something similar to that, automatic start and switchover. Anytime the electricity goes out, it suddenly sounds like someone parked a Kenworth in the driveway.
Bigger problem, our house is all electric. No gas line to the house, it could be done but way too much trouble. If we are home, we have a BIG wood stove that will keep the house comfortable down to about 0'F while it eats lot of wood.