Need advice on 15 month old's naps

[tintinenamerique]

DS has always been a good napper. Her finally seems to be sorting his night time sleep out and is generally going 7.30-6.30. He is always ready for his first nap quite early and I try to eek him out to 9 or 9.30. Then he'll sleep for 2 hours. He was then going down again for another hour about 2.30. Recently this nap is becoming a real struggle and he'll resist and refuse. But he'll be a nightmare by 5 until bedtime.

I don't like the idea of cutting his morning nap as we've all been happier when we haven't tinkered with his sleep, just let him sleep as and when he needs to. But is that the only way to survive this? Or take him out in the pushchair/car in the afternoon in the hope that he'll catnap until I can make the morning nap late enough to be the only nap of the day?

Any experience/ideas?