Thanks, everyone for the replies. We are just starting out so I'm trying to still figure a lot of this out. I eventually would like to have a solar system installed in the Jeep but seeing how we are new I don't want to go all overkill just yet. I have been looking at the Bluetti portable battery systems so I plan on having some sort of Aux power in the beginning.
@genocache I didn't even know there were values to sleep systems like you mentioned with the "R" value so that is something I am going to have to look up as eventually we will move from sleeping in the Jeep to a RTT or even possibly some kind of tow behind system.
@lhoffm4 my wife is a damn lizard as well and is always cold so this is mostly for her as I like having a cooler night's sleep with my COPD. I will have to research blankets may be that we can lay on top of the mattress with our sleeping bags on top of if that is safe. I saw two of you mention diesel heaters, and I have thought about that as I watch Venture4wd and he has a system like this in his Jeep but it seems he has had a few issues with it as well it is rated for certain altitudes? Now I'm not looking to drive up Everest but I try to cut cover my behind in all conditions because we don't know how far we'll push ourselves once we get going down this new Overland venture of ours.
I will take everything here and do some more deep dives into all the solutions and ideas brought up here, thank you everyone for taking the time to reply :)