changing from 2 12volt batteries to 1 12v battery

Know your needs. If you seldom dry camp, all you need the battery for is something to power the lights and have enough oomph to actuate the magnets for the breakaway mechanism. Batteries are not cheap, and if a single small battery is good enough, so much the better.

There are a lot of people who dry camp, but if you don't need a beefy battery capacity, more power to you. It just means more stuff that needs maintained.