So, an update. We left the sleep bag out so that Little Boy could just play on it. When Daddy got his sleeping bag, we left it out, too, and Daddy would climb into his and Little Boy could climb all over Daddy (that was a ton of fun and made for some great video). It took a couple of weeks, but Little Boy will willingly get into the sleeping bag and lay there a bit and play peek-a-boo. We have plans for a trip end of March, so I'll know then if any of this prep actually helps.

We did end up canceling the Jan trip due to colds all around, and then it snowed where we were going, so double glad we didn't go.