Steve and Desi Bang welcome to irv2
With all the problems with the combo large refrig's you may have made the right choice. The only thing I would check for is that they have fans installed thru the rear of refer up to roof vent. I know the compressor has a fan for cooling coils but it would be something to look for on a hot day it maybe not enough.
Others have asked your same question on household refers and Newmar said they don't wire it up to run while traveling. If its cold enough it should stay cold to next destination.
Others have wired outlet to inverter ckt to keep it running.
I see no problem doing that your batts are charged by altenator while traveling anyhow.
on your new coach maybe the new ESSEX OWNERS should form a group to deal with Newmar with all the stupid problems you all are experiencing QC & testing seems to be lacking and poor communication with Dealers on fix's for some of what should be minor problems to fix.
If you feel the sprite to join the Newmar Forum I will input it for you.