Has anyone done the Monticello tour? I see that the house tour is 30 minutes, but I wonder how much time should I allow for the grounds and visitor center? I am buying timed tickets in advanced. We are planning on doing a Mother's Day brunch that morning and arriving at Monticello around 1. That leaves us 4 hours, which I imagine is plenty of time. I can buy the tickets for 1:30 and do the house first, or get later tickets and explore the grounds a bit first. Thoughts on this?