The quick return to 100% is interesting. Have the battery cables been cleaned lately?
Just looking at them will not indicate a bad connection. Try loosening the cables slightly and give them a bit of a twist and see if that does it, otherwise take them off, negative first, clean them with a wire brush or something abrasive, and reassemble positive first.
You could very well have a bad battery and it is 3-4 years old. Having taken it down to dead at this stage of it's life would definitely tilt toward replacing it. Being that age, I wouldn't even bother with a load test unless I had easy access a tester, which I don't. If you want, you could pull the battery, charge it, and then take it to an auto parts store to get load tested. Like I said, the age of the battery would have dictated replacement for me. Having a battery go down in the middle of nowhere pretty well sucks.
Just jumping it will not fix a bad battery.
Bummer on the rough start to your trip.
BTW, it was 78* at my house.
2000 Roadtrek Chevy 200 Versatile
'15 Kawasaki Versys650LT
'98 Kawasaki KLR650