If you want to be guaranteed not to be there during spring break, don’t go during March or April at all. With Easter falling on April 17 next year, the schools with breaks tied to Easter will be there during the last half of the month, and the ones with breaks during set weeks will be there from early March through the middle of April. You might be able to go the very beginning of March, before it gets too busy with SB, but otherwise I would consider February or May instead.