Do you always camp with electric hookups, or do you dry camp, or is it a mixture?
CCA is an abbreviation for Cold Cranking Amps, which is a rating for starting batteries. Starting batteries are designed to start your car, and then be immediately recharged. A starting battery's life is pretty short when it is asked to supply a small load (PUP heater, lights, parasitic loads) over several days. 4 or 5 such cycles will destroy most starting batteries - how many times can you leave the inside lights on in your car, or hours of using the stereo system while parked before the battery won't recharge and start your car in winter anymore?
A deep cycle battery is designed to do hundreds of cycles down to 50% charge, and many more if you keep the discharge smaller. Deep cycle batteries do not do a good job of providing a large current to the starting motor - they excel at smaller currents over long periods of time. Deep cycle batteries are rated in amp-hours, not CCA. Golf cart batteries are an example of deep cycle batteries. Deep cycle batteries cost more than starting batteries and weigh more, too. They are usually installed in banks of more than one battery.
The batteries that are labeled Marine/RV are usually a cross between the 2 types, and don't cost much more than a starting battery. Most that I have seen will do maybe 200 cycles to 50% charge.
So your battery usage matters. A dual deep cycle (or at least Marine/RV) battery install is usually needed to dry camp and run a PUP or A-frame heater and LED lights for 4-7 days - and have the batteries last a few years. If you always have hookups, a single starting battery will probably be sufficient as long as you plug the PUP in fairly soon after arriving at the site. Yes, the bigger CCA is better if the reserve capacity is the same.
just my experiences
2014 Rockwood A122 (dual size 24 Marine/RV for 3 night max dry camping 3 seasons in Colorado Rockies)
2008 Hyundai Entourage (minivan)