Touring the Maritimes with no campsite reservation..possible?

My wife and I are planning a tour of the Maritime provinces this next August 2016. Would like to do it stressless, no reservations anywhere. Is this possible during the peak season? We plan to travel from 9 Am till 2 PM each day. Are we bound to have difficulties finding an RV site (a small class B, 25') at that time of the year?