1193, there are a number of posts about lithium conversion if you do a search. I would agree keeping the design similar (AGM/lead acid) for your described use, if what you had is satisfactory. I did build a lithium iron phosphate battery, but paused the conversion for similar reasons... ie lead acid is working, dry camping in one location for a couple days rather than week or weeks...don't have to increase complexity, DC-DC, new house charger, freezing temp issues, space constraints, etc. This may change over time....keeping it simple is a great idea....
Pac NW and warmer places
1995 E250 EB 5.8 2WD on to a new owner
2006 E350 EB Elect Top 2WD