Transition from 2 naps to 1

[Bugaboom]

DS is 11.5 months. We have been getting up around 5am for the last 3 months. Occasionally he will go to 6 which is more ideal. He goes to sleep at 7, eats plenty, has blackout blinds etc. Up until a couple of weeks ago he napped at 9 and 1, but he is resisting his morning nap and i am wondering whether we should drop it? He slept at 10:20 yesterday for 2 hours, but didn't have another nap so was overtired by bedtime but he slept til 6am. My question is how to transition to one nap? Do i keep pushing the morning nap back? Or shorten it gradually? Has anyone noticed an improvement in early mornings when their baby dropped to one nap?

The early wakings might be the sun and bird song waking him up.
We dropped (and are dropping for dd) at around 18/19 months by having the morning nap on the go eg in the pushchair or car then if they don't fall asleep, lunch is earlier as is the nap. Then super early bedtime.
Made no difference to morning wake ups.

DS is a bit older at nearly 15 months. He had a lovely two nap schedule for months, but really began to fight the afternoon ones and was waking between 5-6am. So I've gone cold turkey on morning nap and am putting him down after an early lunch. He's actually managing ok, but sometimes taking a bit longer to settle at bedtime. It hasn't made an impact on the mornings just yet. I am ever hopeful...!

Thanks for the responses. I might hold out a little longer before dropping to one nap. Was very hopeful that it might improve early wakings!!