Where to go on Christmas Day?

Hi

Coming over from the UK in 2nd half of December and wanted to spend Christmas Eve and Christmas Day at the parks - just seen the crowd calendar for Universal Islands of Adventure is “only” a 6 on both days. Out of all the parks in Disney/Universal is this the best place to go on these two days to avoid the crowds? Would have liked to have done MK for one of those days but it looks like a 10 on both! All thoughts, suggestions and ideas for these two days in Orlando will be welcomed! Even thinking of Blizzard Beach on Christmas Day - my 12yo might even be able to coax me up to the top of Slusher Gusher :wink:

Thanks