I lived in Texas for 5 years & know those trails well
! I think you are very ready for a 50. I would take it easy- no
fasted than 8 hours ride time, and you should have some horse left. if
that is true- you can pick up the pace at the next ride. That ride gets
really cold !! ( Like 20* ) Be ready for both you & your horse.
Rump rug on the saddle, layers, and horse blanket at the vet check. I
think the checks used to all be back in camp- pretty handy ! Good Luck !
We were sleeping in a tent in the snow one year ! - Heidi
Helly