Most Efficient Offline Base Map

New user here.  We travel remote areas of the US via truck, make a camp & then hike, bike, and/or packraft from the camp.  We're interested in moving to Premium Gaia GPS as a potential "single source" mapping solution for two phones, one tablet and two Windows (Win 7 & Win 10) laptops.  Currently we use a variety of programs that each do something well, but none do everything adequately.

Because we travel with only a general plan it is difficult to download specific maps for a particular trip outside of cell coverage, thus we need to download an efficient "base map" for the western US.  I'm curious which of the available maps (Premium) you all have found to provide great road & two-track detail with the least space and download-time requirements?  Space isn't a major issue as both phones and the tablet have 256 GB Samsung Evo cards.  Thanks for your help.

Howard Snell