I am with the person who said close off the bedroom and cool the living room area, I would add that if you have an electric vent in living room put that on for the first few minutes of the A/C is on so it draws out the hot air which rises as the cool air drops down so the hot air is being drawn out. We have 50 amp service and we have two air conditioners but rarely run the bedroom A/C but it is also rare to be in 100 degree weather. Also consider that lots of campgrounds cannot handle every one using both A/C units so it browns out the electrical and no one has A/C. Fans blowing the cool air around helps as well. Best of luck!
Outside of adding a second AC this is exactly what I would do as well. If this is only a temporary thing once or twice a year it's not all that much hassle. I agree with you about if everyone had two AC's a brown out will ensue..than nada AC for anyone.