We went once over thanksgiving. (Could book no other time)
As advised by many we decided to have a quiet day and not do a park. Most shops closed.
I would also keep an eye on the local news for travel updates, especially if you want to travel to say the coast.
Just think of our "Easter weekend" on the roads. No so busy on the day but the day before and just after can be a little busy.
Do not be put off totally as their road system is a lot better than our one big National car park (LOL)