T.W.
My son gave his up at 15mo. My daughter gave hers up at 10mo (yes, way too early, but it all worked out fine). After dropping their am naps, both of my kids wound up taking one long afternoon nap, approx. 1-4pm. My daughter's started out at 2 hours, but more recently (she's 21 mo. now) it's been 3 hours. You can try it & see how it works. I think he'll adjust b/c he seems to be in the right time frame for dropping it....however, if he is sleeping well at night & napping well during the day as it is, I personally would be afraid to mess with it b/c as you insinuated, it could inadvertently affect his nighttime sleep. I guess you have to decide how important it is to have the free time to run errands now vs. in a couple months or so.