I ride solo 99.9% of the time, but in the pinelands of NJ, which is not huge, at least out to any road. You can walk out from anyplace in 12 hours tops.
Its easy to get a bike stuck though, its very wet in a lot of places.
So I never bring anything, only a cell phone which works in spots.
I tend to tell no one where I am going (out riding) because I never know where I will end up.
The only time I almost had a problem was after a bad crash 10 miles into the woods. Enough broken bones and injuries to where I could not lift the bike.
Walking out was not a good option, I had slight cell coverage.
So I sat there thinking about it for a while and some guys rode up and found me. That was unusual, but there was an enduro race the next day in the area.
I could have made a call (maybe) and after many hours, they might have found me, otherwise, it would have been a close call about me getting out alive.
The doctors told me I was lucky to be alive at all, but I do not look at it that way.
Lessons learned? Get a lighter bike for dirt riding.
I would feel different in places more vast.