I would say that's far too long of an A to BT hun. You'll also have a big developmental leap around 1yo which either causes them to sleep more or less for a week or two
I would keep to a 12-hr day at absolute max on a1.5hr nap hun. Perhaps even 11.5hr. OT could have definitely started to kick in too.
Ok if the wu isn't too bad and they're going back to sleep, do you want to power through with the one nap or do an odd 2 nap day to keep the OT at bay?
Personally I would power through but my DD dealt with OT well, it seems like yours is too? I know it's a pain with the EW, but they are going back to sleep.
I would push out that first nap again. An hour could definitely be indicative of an UT nap. How about tryin for a nap closer to 4hrs 45mins? I would hold that for a week and bring BT much closer to 12hrs after wu.
So for example.
Wu 7,30
A 4hrs 45
S 12.15-1.45 (or more hopefully)
A 5 hrs 15mins
BT 7
If the nap is longer than 1.5hrs you may be able to push BT back a bit?
If you wanted to do the catch up nap, I would try a quick car nap or buggy nap at 11am for 15mims then do nap at 1.15 and hope for a 1.5hr nap which should get you close to your usual BT at 8pm. I would probably only do this the once for now though as it looks like they're starting to get used to the one nap routine, it just needs to be placed better in the day xx