DL-
There are some who would argue the reason to "go dry camping" was to escape civilization, not to be fairly civilized while in the boonies. You may even find it quite pleasant to get away from some of the "civilized" options.
Dry camping can be VERY relaxing and many enjoy the dry camp atmosphere.
You can learn the alternative to many, many traditional ways of doing things in your RV. Like Marv said, you can enjoy a good cup of cowboy coffee. Don't need no stinking AC 120V.
What causes most people problems is water conservation. You learn not to "run the water" uselessly, you use already used water to flush the toilet, many carry additional water jugs in the tow vehicle, plastic utensils are used vs. items which need washing, the options match the ingenuity.
An additional 12V battery (be sure it’s deep cycle) is a definite advantage. Tie it into parallel with your other battery and you have doubled your amp hour capacity.
No inverter is not a big deal really, if you lean to do without 120V for the time your dry camping. Can’t use AC, no microwave, no AC computer use, you use safety razors vs. electric shaver, no 120V TV (oh my gosh how will we survive….lol), and running the heat fans can kill a set of batteries in one night.
A true sine wave inverter can be quite pricey, the battery bank to support the inverter in itself can be a significant weight issues in an RV, and I personally would not go out and buy one just to have 120V while dry camping.
Many think the money spent on an inverter is better put towards one of the new high tech, quite, generators. Not only will the generator power many of your 120V RV appliances, it can of course be used to run a battery charger to recharge your deep cycle batteries.
The people you will be joining probably are seasoned dry campers and will gladly help you learn the dry camp lifestyle.
Bottom line, before you spend lots of money (not considering the time to put the new systems all together) go dry camping with your friends, and take in all their dry camp suggestions so you can make your own educated decision on which options to go with.
ENJOY your dry camp adventure.