R is 13 months and doesn't seem anywhere near ready for 1 nap yet. He still goes down for both naps pretty easily (even though sometimes the morning nap can be short).

T went down to one nap at 14-15 months. He started fighting his afternoon nap, and I had become a SAHM in a new place and all the kid activities where I could meet people were in the morning. So, I switched him. He never slept more than 1.5 hours on one nap until he was like 2.5....and then soon after gave up his nap! So, I'm really in no rush to switch his brother. It's sort of a pain on the weekends to get home for 2 naps...but R is fairly flexible and will take his afternoon nap a little later when needed. And he gets up at 530/6 so his morning nap is around 8:30 anyways, so we can usually be out of the house from 10-1:30 or so one weekends or days when I'm not working. T doesn't nap at all, so that's really not a consideration!

Did you switch LO2 to 1 nap to accommodate the older sibling's schedule or for convenience?