If you’re going to have to place lithium batteries outside and are going to be in freezing weather, then you need to get either self-warming batteries such as relion or a battery blanket. However you didn’t state if you were full time and have been living a nomadic life for a while, or if you were just planning at this time. Also you didn’t describe your existing rig.
If you are in a small rig such as a van or class-b you are already limited in space and if your existing batteries are exterior, then you have to think really carefully if you are willing to give up interior space for batteries. Also you would potentially have to do some rewiring and swapping charge controllers to move your batteries inside.
You could use AGMs. They are better in cold weather environments than lithium. They don’t last as long as lithium and you have to be a bit more careful not drain below 50%. The main reason that lithium tends to last longer than AGM has to do with how you charge them. Way too many folks don’t understand the bulk/float phases of charging and think that if the just ‘top off the batteries’ at the end of the day to get to 12.6, then they have done a good charge. Nope - and doing that will shorten the life of the battery. However I also know of some folks that pretty much destroyed their lithium batteries after three years due to improper charging for lithium.
I have AGMs in a class-B and have long considered switching to lithium. I like that I’d have more power, don’t have to fully charge them on a daily basis, would reduce my rig’s weight, etc. But my batteries are currently exterior so would need to take up interior space for the heat reason. Also, while my AGMs are currently over three years old, they are holding their charge very well. So if I’m sustaining 14.4 voltage for a couple of hours in the peak of the day, am at 12.7 20 minutes after the sun goes down, and am at 12.4 in the morning after running my compressor fridge over night, then why swap them out?