How much for parking in January, will be for 7 days? Will I need book advance or can we book when we get there?

You can do either pay in advance online or you can pay when you get there. I paid in advance and printed the confirmation. If you go to their website you can type in your expected travel dates and it will give you a precise dollar amount.

January? It's usually 12 to 16$ day, best to book online in advance but you can also pay at the lot when you drive in.