Sorry to be so vague, but honestly, all you can do is try. If he's not taking much at the cluster feeds any way, he might take more if the 2 are just 1 KWIM? As far as the naps, you can still be flexible about it. Take today for example, since he had a short pm nap, you could still give him the catnap. Anytime a situation arises where he has less day sleep than usuall, if he'll still take a catnap, by all means let him. I only dropped my dd's b/c she started refusing it, but I wasn't ready for it, trust me. It did take her a long time to adjust without that last nap, but she had always been a very POOR day sleeper. However, when her naps straightened out and she was on 2 (at 6 mos), they were both 2 hrs. So, I'd say he might do the same or a bit more at his age, and probably 12 hrs at night, maybe 12.5 until he adjusts to not having the catnap.