Oh ladies please help me...

Esme is getting such a big lady, and her sleep patterns are changing. I've been trying to move her from 2 naps to 1 as she's never tired at bedtime if she has 2. However, this has only worked about twice and the other times i've either put her down for 2 naps afterall, and listened to her jumping about in her cot for 2 hours after bedtime, or spent most of my day with an over-tired whingeing tot. Pretty grim for both of us.

Our usual routine is:
8-8.30am: get up
11-12pm: morning nap
4-5pm: afternoon nap
8pm: bedtime (i run her bath at 7pm, then bath, dress, cup of milk, cuddle, songs, brushed teeth, story and lights out, i usually leave her room about 7.45pm)

I'd like to move to:
8-8.30am: get up
12.30 or 1pm: nap (for as long as she needs at this point)
8pm: bedtime

Most of the time she's so grumpy by 11 that i end up putting her down.

Yesterday i got her up at 8.30am, and though she got sleepy looking at 11.30 i kept her up and gave her lunch at 12noon. I put her down for a nap afterwards but she only slept for 40 minutes! SHe was really grumpy all afternoon after that, though her teeth are coming through still (the 5th one grew in about 3mm yesterday, poor darlin) so that was a contributory factor. We ended up going for a walk to the shop yesterday which made bedtime a bit later but she fell asleep while i was reading her story at about 8pm.

Today i got her up at 8am, put her down at 10.45am, and she slept until 12.30! Then we went out for a walk and a play in the park (and she can only JUST walk so this tires her out) in the afternoon. We came back at 3.30 and by 4pm she was laying face-down on the laminate with her comfort toy under her head and her thumb in her mouth, so i put her down again for another nap, but this time i went and woke her (rather than letting her just sleep as long as she wanted) after an hour and she whined and cried until her daddy arrived at 6pm. He put her in the bath at 7.30pm and she was in bed by 8.15pm. But she jumped around in the cot for a good 25 minutes....

Where am i going wrong!? If i let her sleep as long as she wants she isn't tired for bedtime until 9 or 10pm! And if i wake her from a nap or make her wait for one she's really grumpy. I want her to be happy, but i don't want her demand-sleeping as i'm a single parent and i've gotten to the stage of hallucinating through sleep deprivation before (when she was new). She doesn't cry usually, just jumps about and plays, should i just stick to the bedtime routine even if she plays instead of sleeping, and let her sleep all she wants in the day? I'd rather she got a good long sleep overnight as even just waking once in the night (with sore gums etc.) makes her tired and crabby all the next day.

Any ideas would be most welcome....