Yes I asked this question on TripAdvisor and no responses!
Just in case anyone else is interested- I contacted the tourism office and you can pre book bike rentals there. They rent them from 10:30 to 4 on Sunday’s which is plenty of time.
I booked a tour at Moet for 3:45 pm. I contacted the Paul-Etienne house which is open for tastings on weekends as well! So our plan is to visit Paul Etienne for a tasting and buy a couple bottles to bring along in a back pack while we cruise the country on our bikes and have a picnic lunch (which I’ll bring from Paris). Then, back to town to tour Moet.
Finally, we will eat dinner at a restaurant open on sundays (going to make a reservation just in case) and then head back on the train to Paris!
I appreciate everyone’s help!