Are they completely dead or just weak (turns over real slow)?
Also, what is the motor? A gas V10 probably. A big diesel...less likely.
If you have access to shore power, better to get a charger on it
If you do jump start, make sure the car engine is left running, so you don't kill the car battery. Also, if you get the MH engine running, operate under the assumption the battery won't restart it, so don't shut it off unless it's somewhere you can leave it.
Removing the battery terminal (or putting in a disconnect switch) is a good idea but doesn't help you now.
If you are lucky, the battery will be OK but plan on replacement.