Most everything should be busy. You can try searching the 162-174 range, but don't expect to hear much. USSS will be full encrypted.
Keep an ear on the Asheville TRS mainly. APD had most of the fun last year on their events/special ops channels. The database is extremely accurate so go off that for best reference. I didn't notice much of a difference on the county fire/sheriff channels minus units checking out of service to standby for the event.