j.and.e and Jem88 - sending (((hugs))) your way, don't have any more advice for you, Claire and Kara being so helpful as always

Hmmm.... I really don't know what's going on with us! Last Thursday was DS last ever 2 nap day at his childminders - we've decided! Yesterday was approx:
06:30 Up (after a shorter-than-ideal night)
11:45 nap (woke crying at 45mins and 1.5h but quickly resettled himself each time ... then was still asleep at 2:20 when I went in to wake... but he didn't rouse easily so I waited a bit before trying again... 2:30 - managed to wake him!)
7:20 PD, took about 20mins to settle but was starting to show slightly OT signs...
Today:
06:30 Up (assuming he woke around then, I woke to my alarm!)
11:45 nap - only 1.5h, tried to resettle for ages but he really didn't seem to need more sleep??? Was quite happy chatting until he got bored!
6:30 PD (so already >5h A time from shorter-than-usual nap), but it was babble, babble.... quiet.... babble, babble.... quiet.... babble, babble etc until (hopefully!) finally asleep at 7:20 - ie ~6h A time after short nap???!!! Fearing an OT EW tomorrow...
Ok, so maybe 5.25h 1st A time is too little if he's had a good night's sleep, so I might try pushing to 5.5h after a good night, but I just don't get what to do after a shorter nap? It just seems to take him an hour or so to settle, whether I give him less A time to account for the shorter nap (as used to work...) or push him until closer to the BT he would have had if he'd had a longer nap. Doesn't quite seem right. I guess I should maybe expect a jump in A times now since we're hopefully out of the really ill horrible few weeks so he's getting more quality sleep, and sleep needs start to reduce after 18mo anyway, don't they? But I'm really not convinced by the 6h A time after a 1.5h nap, when just a month ago (before getting ill) he was good on 4.75h after a 2h nap, plus a 10-20min morning nap! He's always made more gradual changes in the past...