The corps spends the first two weeks or so of Spring Training in Johnstown, PA, then travels by bus to Ada, OH for the remaining couple weeks, then starts the tour. That has been their schedule the last two seasons, and will be repeated this year. The corps leaves Ada June 16 (a handful of days earlier than usual) and instead of driving to Indy for the season opener, they drive on to Nebraska (and rehearse on the 17th), then to Wyoming (and rehearse there the 18th), then to Utah (and rehearse there the 19th), then to Nevada (and rehearse there the 20th), arriving in California the 21st.
To be honest, I don't believe the additional miles on the front end will necessarily add much, or any, to their overall budget, because the corps will simultaneously be saving the cost of renting dorm rooms for ~200 people for the several additional days they would have stayed at Ada had they only been heading to the Indy opener. They're also doing 7 shows in California, all clustered around SF and LA, so there are several days in Cali where they are not traveling significantly at all. They're also cutting out the Florida leg of the tour, which was lengthy the last two years. Someone can probably run the exact mileage on google, I suppose.