I don't usually shorten it, because if I manage to resettle O it's usually a pretty quick process and he'll often go back off for over and hour (I hate to wake him from naps, even though I know that's not 'by the book'). Although if he's seems really sleepy or cranky I will.
So we had a solid wake up time of 7:30 this morning and I lengthened is A time from a usual 1h25min to just over 1h30min. He woke happy after 45 min so I think if I get another solid wake up time tomorrow I'll aim for 1h35min and see how that goes.
After not being able to resettle him this morning (too happy and alert for that to work makes me think he was UT for that nap), he's down for his second after an A time of 1h25min. Longer than I would have liked after the short nap, but errands kept me out. He's been down almost 45 minutes now, so we made it past the dreaded 30 minute mark, we'll see if he makes it through the transition. What a saga our lives are, eh?
Even if everything works out splendidly today, I may never be able to repeat it as DS1 is at daycare today, so not throwing in his usual monkey wrench. =)