Howdy Kari, I say go for that 50. From my experience, a slow 50
is easier on my mule & me than a fast LD. (Not that I know your LD
speed) You know, the worst you could do is not complete---from what you
said I'm thinking that would be because of your body, not your horse. I've
seen you at rides & know you will take care of your horse. Heck,
you got 12 hrs & there's no shame in not finishing if that day is just
not your day.