Well, last night didn't go as hoped -- he got up 3 times again, I think! It all started to blur together, but I don't *think* I took him out of his crib. What was weird though is that the tent wasn't even zipped, so I don't know what he was so fussed about -- MAYBE teeth!?
Anyway, the afternoon nap was fine, but again only half zipped. He did take a full-length nap, and was a bit edgy all day. So it may in fact be teething pains, as he seems to "sleep it off" instead of lose sleep like most toddlers.
However, tonight at bedtime we had a breakthrough. He was awake when I put him in the tent, and asked for (signed for) "more" songs for a 3rd time. So as I hummed, I managed to zip up the tent. He only fussed a bit, so I walked out of the room. Then he wailed in protest, but only for about 30-45 seconds. I haven't heard a thing since, so here's hoping tonight goes better than the previous 2!