We haven’t had any problem charging in campgrounds. But a couple things.
Where we are 50 amp is kinda rare. We charge a lot from a 30 amp plug (so max 24 amps at 120 volts). We plug in either the car or the trailer not both and we tell the operators that.
Some campgrounds do a forced upgrade to 50 amp even though we only need 30 amp. That’s fine with us. Usually 20 bucks more.
More and more campgrounds are adding dedicated EV charging. Not as convenient as it’s usually not near the site but still ok with us.
We have toured all over Canada and extensively in BC. Charging has never been a problem. We leave on a 6 week, 10 western US state tour in a few weeks. Should be fun.
At superchargers or DC fast chargers we have to unhook one out of 5 times. There is usually a way although generally speaking non tesla charging is more trailer friendly.
Typical 30 amp charging for us in our combo.