Hmm...yes, I would stretch his first A time. If you'd been trying to get a 1.5h+ nap on 3h20 A time, and you've not been getting it, I would definitely add some more. Maybe, like, 10 minutes. Then go ahead and cap his nap to 45 minutes...if he suddenly does a 30 minute nap on the new A time, we'll know that he wasn't really ready for the jump.
He did do a full A time on the 1h nap...so I wonder if nap #2 was really OT. I'd try putting him down like you've planned (at ~3h A time). So, tomorrow, we're *thinking* will look something like this...
Awake: 6:30
A time: 3.5h
Nap 1: 10:30-11:15
A time: 3h
Nap 2: 2:15-3:45
A time: 3.5h
Bedtime: 7:15
That's just a guide; and I would definitely cap that 2nd nap. The idea is that the A times will increase all around and the first nap will get shorter, thus moving the 2nd nap closer to the middle of the day. LOL, sounds good in theory, right?
Give it a shot tomorrow
I'd also try for a slightly early bedtime tonight since he hasn't slept well today.