12 Volt versus 6 volt-Rarely boondock

I rarely boondock,and need new batteries. My marine deep cells are shot, and I am wondering if I could get by with only one 12 Volt, Group 27, or should I get 2 6V golf cart batteries. I almost never boondock, so dont need much power. Too many other items to repair right now, and dont want to spend hundreds if I dont have to. Thanks for the replies.

Kevin