Hey Loujo- how's it going with the nap schedule? I have the same predicament as you - an 11 month old that needs to fit in naps around the preschool run. He was on a 2 hour A time and then all of a sudden stopped. Overnight, just as yours did. So I'm trying to figure out his magic A time, which I think is 3 hours.
Part of me wants to just let him take the lead for a few days so I can see when he wants to wake, nap, sleep, but I'm just so worried about undoing all my hard work of protecting his sleep so he's not OT.
Check in, if you can, and let me know how it's going for you!