50 Amp question

WE may be buying a new fiver with 50 amp. Wouldn't you know i just had a 30 amp service installed near my current trailer. The new rig does not have a 2nd A/C so it is ok to use a dogbone and just plug it into the 30 amp service for long periods of time? The only thing that will be running is the fridge and A/C when I am loading the trailer or camping with it.

Any other advice you folks can pass along?