Coming back to this thread, in the end, our battery power needs dropped slightly because we spent a few days at a campground with power. That being said, the following combination ended up working out well:
1. 5 outlet power strip connected to AC power plug in truck bed.
2. ARB fridge simultaneously plugged into power strip on AC and into G31 battery for DC (it auto switched between the two; when truck turned off, ARB ran on DC and vice versa when truck running)
3. Schumacher charger plugged into power strip and charging G31 battery (turns out the Schumacher automatically turns on after 10 minutes at the low amperage setting if you don't hit the start button before then, so it was charging more frequently than I thought.)
4. Goal zero AC charger plugged into power strip
5. Switching from AC charger to DC charger for CPAP (power usage dropped a lot with this change)
Due to the driving all over Grand Teton and Yellowstone, the batteries didn't spend multiple days running without charge. So, it was never a deep recharge and therefore this setup worked out quite well. I ended up not bringing the solar panels, which was just as well, because we were parked in the shade in GT and it rained all three days in Yellowstone.
Thanks again for the feedback on this idea.