My 18mth son still has a morning nap of 20-30 minutes on the days he is not at nursery. He usually starts his day between 6-6.30am, never having slept until 7am. He does not seem tired at home but settles to his nap in 5-10minutes. When at nursery he has a much earlier lunchtime nap so manages to stay up all morning. We are going abroad in 6 weeks and I don’t really want to have to return to our room just for this quick nap.
My son naps at 9.30-9.50am and 1-2.15pm when at home. At nursery he goes down between 11.30and 12 midday and naps for 2-2.5hrs.
When a toddler first drops the morning nap he may need an earlier lunch and go down for his long nap at 12.30pm to prevent him from becoming over tired. These times gradually move back towards 1pm as he becomes more used to being up all morning.
It would seem that if you want your son to have his lunchtime nap at 1pm he does still need a short nap in the morning. If he begins to resist his morning nap altogether, not settling to sleep at all, then it is time to drop it but be prepared to follow the above advice. In the early weeks of dropping this nap you may need to juggle things on a daily basis. He may need a morning nap once every few days for a short while until he learns to cope well with being awake for the whole morning.
If you continue to want your son to have a 1pm lunchtime nap whilst you are on holiday and he is still waking early in the morning it will be helpful for him to have a short rest of some kind during the morning. You could try taking your son for a walk in his buggy at 9.30am, finding somewhere quite quiet and see if he will drop off for a short catnap. Even if he does not sleep he will be having a rest which means he will not be over tired by lunchtime which could result in him not eating well at this meal.