That question can get real complex in a hurry...
CCA in an RV application isn't important. CCA refers to a battery's ability to provide a lot of amps for a short duration (while turning over a car's starter-Cold Cranking Amps). Your RV doesn't have a starter and the amperage needed for an RV has to be not as high in a short burst, but, higher for a protracted time and those batteries are measured in AH (amp-hours). The RV/Marine batteries are also different from an automotive battery in that they are "deep cycle"...they can be drawn down further and recharged numerous times without harming the battery, an automotive battery won't survive long when drawn down deeply and then recharged.
What you want is a deep cycle, sealed battery (RV/Marine), not an automotive battery. You can get by with less AH's if you primarily stay at campgrounds that have shore power, but, if you boon-dock a great deal, you'll want as many AH's as you can get your hands on. Hard core boon-dockers, quite frequently run multiple batteries and some even go to multiple 6v golf cart batteries (the max in AHs) in order to provide enough "amps" to run everything they need. They'll use generators or solar to recharge those batteries and can stay off the grid almost indefinitely.
So don't look at batteries and their CCAs...those are automotive. Look at deep cycle batteries and their AHs, and the more AHs, the merrier