Well, I've tried two bottles to date. First was one I'd stored in my room, here in DC. Ambient temps were probably in the 70s. After about 9 days, the level of carbonation was quite high! The "pop" when I opened the Grolsch bottle was quite intense. I also opened one when I was back at the folks' place. That one had been stored in about 60-68 degree temps. Not nearly as much carbonation, so I'm not concerned that they'll over-carbonate, especially as the temps move down. My last two here at my room are in my fridge, so that they don't get too highly pressured.
I liked the result -- it was mellow, with very little hop character (just the way my mom and sis-in-law like their beers, so I'm expecting they'll go for it). A bit of honey taste, but not overpowering. It'll be interesting to see how they taste in a month (I plan to bring them out during Thanksgiving). I'd do this recipe again -- maybe not for myself, but for guests.
So, the braggot experiment went well -- I'm thinking I may have to check out additional recipes and do another one over Christmas break...!