Yeah, resisting bedtime in combination with the nap resistance makes me think 1 nap as well. Part of it may be the time change; even though we didn't change Leah Catherine's day, but rather just change the clock times, she seems to sense its different.
I have spent a lot of time thinking about your situation this weekend and think going to one nap is the way to go as long as M is feeling better. I know others may disagree, but things never got any better for us until we made the switch. I tried one nap once when she started refusing naps the first time and it didn't go well (she got a virus in the midst of it) so I backed up to trying 2 again. She adjusted back into that, with 2 short naps just like M and then she started fighting the PM nap. I so wish she had just fought the am nap - it would have made it so much easier for sure.
I think for M it needs to be a gradual switch. I also think you need a plan, because I sense that you are a huge planner like me. So I'm throwing this out - kind of thinking as typing.
M is taking her am nap (with the time change) at 10:45, right? Technically she's been doing this time for 6 or so days, I believe. Would you consider going back to one nap again or do you feel more comfortable doing 2?
The transistion is hard, but we'll be here to support you. Our goal is to protect her nighttime sleep, because you and M both need that to be able to handle whatever the day brings. My personal thoughts are that the sooner you make the transition, the sooner that one nap will lengthen for you guys. We've been sticking to the same schedule for 20 days now of just one nap and things are so much better than before. Total sleep seems about on par with M, its just allocated differently now and she's a lot happier upon waking from naps. I feel better because I feel like I can finally enjoy some of that Y time that everyone talks about, LOL. It's not always the perfect nap of 2 hours, but more often than not its an hour and 45 minutes to 2 hours. I can live with that, and I think with time it will even out. The hardest thing for me has been to resist the urge to over-tweak her schedule - and the only way for us to work it out was to pick a set naptime and go with it.
So basically, I'm asking if you're willing to give the set naptime another go? I really believe you will find success with it. M is doing better right?
One more thing that I forgot to say. Would you be willing to consider waking M after 11.5 hours of night sleep? I think doing so might garner you a longer nap during the day. That's something you could try either A) if you stay on 2 naps a day or B) after you make the transition to 1 nap a day. We transitioned and then realized that if she slept longer than 11.5 hours at night she just wasn't going to nap all that long during the day. So if she's not up after 11.5 hours (and she's not seemed OT - its kind of a judgement call that I make by watching her cues), I would typically wake her. Lately, however, she's been doing it on her own as she seems to be getting more settled into the 1 nap routine.