Install USB ports directly connected to your 12VDC RV wiring. That will help charge any USB cabled devices, i.e. phones, tablets, etc.
You will still run down your batteries unless you have a way to recharge them. Solar or generator or both are the real options if you do not have any shore power connections. Solar is very nice once setup as you don't have to really do anything where your batteries will be charging during the day if the panels are in the sun. Con is the cost but you could do a reasonable 200W system with 2 GC2 6V batteries and accomodate most lower power electronic items with a reasonable 1500W inverter. Forget the air conditioner, microwave, hair dryer, electric coffee maker or other items with heating elements. But again, the con is the price. What I've listed out would cost somewhere in the range of $1000 - $1200 US dollars if you install it yourself. Honestly though, dry camping with solar is worth the price compared to listening to even the quietest generator.
A 2000W inverter generator would run most of the items in your RV minus the air conditioner however there are some reporting running an A/C on a 2000W inverter generator. Best bet there would be a single 13.5k A/C with an Easy-Start and running at lower altitudes and even then it may not work but many report good luck with that.
I have (2) Champion 2000W Inverter Generators with a parallel kit to combine them and have been mostly happy with them. I wish there were some high altitude jets for them but the price was difficult to pass up when I bought them a few years ago. They are reasonably quiet but they are now backup to my solar panels or if I need to run the A/C.