Number one thing is crating, and you have that absolutely right. That will keep them from getting into anything that could harm them.
Number two thing is some sort of monitoring device so that you can monitor the inside temperature of the trailer. Loss of AC is the main thing that could endanger them.
Something like this monitor system will send info to your phone, although obviously you must have a decent cell phone signal to get the info. Some variety of internet service has to be available for the monitoring device to access in the RV, too.
Next on the list would be a camera system that you can monitor from your phone, although that's not as urgent if you have the dogs crated and temperature monitored.
Single empty-nester in Middle TN, sometimes with a friend or grandchild on board