
Well, if he's really unconvinced that he should have an earlier naptime, then I'd suggest an earlier bedtime. Based on your routine, he's getting about 12 hours sleep (less when the nap isn't great), and that's not really enough.
An earlier bedtime should help him catch up, and be much less cranky (then you might find him more amenable to the earlier/longer nap).
Btw, it's not true that later bedtime = later wake up time. In fact, most people find the opposite. The later the lo goes to bed, the less rested he is, so, when it comes to the light stages of sleep in the early morning, they are more likely to be disturbed and wake early. At that age, I always found my ds slept better, with fewer NWs and a more civilised wake up time in the morning, when I'd put him to bed earlier.
I'd aim for him to be in bed around 6.30 - 6.45pm, although perhaps you should do this gradually, say make it 15 minutes earlier every day, so he doesn't find it a shock and fight you too much. I always made it a rule that ds was in bed asleep 12 hours after he woke up, then he was getting a good 12 hours sleep at night, and it wasn't such a disaster if the nap went badly.
HTH
