We have natural gas here, and before 24 months pass, we will have a whole house automatic system that is outdoors. We live in town so we do not have a well pump, or water heater to deal with. City water, gas furnace and water heater. We can get a system that is totally automatic and will power almost everything for about $7k installed. When on the generator, using the stove or oven would be a minimal thing. But, microwave, toaster oven, electric skillet etc. are all usable. It will easily power my A/C in the summer at the same time.
It starts itself once a week for testing. Takes about 10 seconds to fully kick in when the power drops, and disconnects seamlessly when the power comes back on.
I have two clients with these systems and they love them. I like the idea of totally automatic and seamless. I have all the electronics in my house on Battery Backup which will effortlessly keep them up while the system starts, so not even a reboot when the power goes down.