We have plans to go in March. Which week depends upon when I can drive at Daytona with Petty...they haven't released their 2016 schedule yet either.
If you go, games in Orlando vs the Barves, and in Tampa vs the Yankess - both great venues - so check out the Spring Training schedule. Viera...not so much...and the young guys generally play on the road.
Boy and I went in '08. We stayed in Daytona and it's not that far from Viera.