Funny thing happened on a recent campout. For breakfast, I wanted to run an electric flat griddle and an electric skillet at the same time. And oh, the air conditioner was on, and the water heater was on electric, and we had 2 televisions running and the satellite dish receiver, and a couple fans. I'm on a 30 amp service with a 30 amp plug with a trailer designed for 30 amps.
Well, as soon as I turned on that one last light, poof! Out she went! I knew I pulled too much amp draw. No problem. Shut stuff off, and go to the electric post and flip the breaker. Breaker not tripped.
No problem, it must have been my surge protector. Nope, it takes about 2 minutes for it to reset, and it wasn't tripped. Enough time had not passed to reset yet. So I'm thinking, "What the heck!"
So went inside the camper and checked the converter and all the AC breakers there. Nothing tripped. Then I noticed the main breaker on the power supply converter ... tripped!
Kind of funny that the trailer main breaker flipped first before the surge protector and the breaker at the post. I guess my camper is well protected.
To the OP, you can comfortably camp on a 20 amp. The most that will happen is the breaker will pop (somewhere). Just turn something off, reset the breaker and use one heavy-hitter item at a time. You'll have a great week-end!