Welcome to the club!
We have a FAQ on efficient driving in the Prius forum area. Also, it is a good idea to start recording your fill-ups in the database.
Considering your commute distance, if you can stay out of the 39-50
mph range, either go slower or faster, you'll get great mileage. You will pretty much eliminate the warm-up overhead but it is still a good idea to keep the speeds low for the first mile or so in the morning. Do take a look at the mileage database and you'll see most of the folks with longer drive segments are getting terrific mileage.
You have a 2.5 hr. commute each way, right?
Bob Wilson