Re: Battery Sizing - am I crazy?
Unless you have the option of hand starting your engine, I'd go with two automobile size deep cycles on a selector switch. Alternate them for starting the engine and switch to one only for house use - then if it dies you'll still be able to start your engine in the morning.
Switching to LED lighting will help a ton as well.
I know Deep Cycle batteries are not supposed to be starting batteries but I've used them that way and got nine years out of one $75 one with no problems.
I, myself, personally intend to continue being outspoken and opinionated, intolerant of all fanatics, fools and ignoramuses, deeply suspicious of all those who have "found the answer" and on my bad days, downright rude.