Golf Cart battery sizes... Decisions, decisions

At least around here, the Duracell golf cart batteries from Sam's Club are (were) made by East Penn. Perfectly OK batteries so far as I'm concerned. In the summer, and without solar, I can probably get about seven days from the pair with modest light and gadget usage, but some fridges and whatnot use more power than mine. I say probably because I've yet to have reason to boondock for that long in one place in the summertime.