Thanks, @westend. Reading there and in the thread @smkettner linked to on the previous page, I can see that solar would be a Project. I have a moderate amount of experience with DC systems (design/build) and I can do it, but there would be some reading involved, first.
So it's not a solution I can implement this week, unless I drastically misunderstand what's involved :). Having recently done some reconfiguring of winch/inverter/house battery, I can say that even sourcing heavy gauge wire is difficult, locally. (I ended up buying jumper cables and cutting them up. But real copper cables are getting rare, too.)
Speaking of jumper cables, when people mention in this thread about using them to connect house battery to alternator -- are you folks talking about driving down the road like that? Or running the engine for hours when parked?
I do want an isolator. Surepower says theirs won't work with our AGM house batteries + flooded starting battery. I gather there are other brands that can handle mixed types -- anyone have time to tell me which ones?
There is so much to learn!