You know your body best, but it sounds like you're ready to do the 26 (and seems like that's what you've got your heart set on). Go for it!!! Just make sure DH doesn't sprint out first thing. It would be sad to have to load him on your handlebars for the remainder of the ride.
I usually take it easy the day before a really big ride/training session/event. I still will work out, but just will keep the intensity low.

Have fun!!!