I plan on bringing 2 outfits per day for everyone, plus an extra 1 or 2 outfits for the kids "just in case". I don't plan on doing any laundry as we are only staying 4 nights. My oldest dd is planning on bringing 3 outfits per day for her baby (6 months).
For December planners: we've been there twice in December. One year, it was HOT and we had to actually go out and buy more shorts and tshirts because it was "supposed" to be cooler, but actually got to be in the upper 80's. Last year, it was COLD and rainy. We had to wear our shorts during the day because all of our jeans were wet from the all-day raining going on. It was chilly during the day, but it felt good in the sun (it was in the lower 70's). In the evenings, we had on layers with sweat shirts and long-sleeved shirts, sweat pants or jeans. For
MVMCP, we had on layers of sweat shirts and long-sleeved shirts, PLUS our winter coats and mittens (and the kids were still cold).
You just don't know what kind of weather December will bring, so plan on bringing EVERYTHING (lol). In retrospect, the cold is easy to deal with, it's when it's been raining ALL DAY LONG and it's cold that's makes it uncomfortable.
We're leaving in a couple of weeks, so I know it will be hot. That makes for easy packing!
Mary