If you plan to loop in one year, I think that is cutting it too short.
The Great Loop route is seasonal: Chicago to Mobile in the Fall, around Florida to Jacksonville during the Winter, up the east coast to the Hudson River in the Spring, and around through the Great Lakes in the Summer.
There are many risks that can cause delays: weather, mechanical breakdowns, damage due to grounding or hitting underwater objects, sickness or injury, waiting for a window to cross the Gulf, etc. Additionally, as soon as you get schedule driven, the trip is not fun casual cruising but all worry and a tendency to take risks just to get to the next port.
We planned a year trip leaving Lake MI in September. All went according to plan until we got to the Erie Canal and it was closed for 3 weeks due to flooding and damage to the locks and dams. We ended up storing the boat in Brewerton, NY for the winter and going back the next summer to enjoy some of the best cruising which is the Trent Severn Waterway, the Georgian Bay, the North Channel. That turned out to be a great plan which you might consider.
Our trip was 305 days of cruising covering 6,850 miles. The pace was comfortable for us. On the average, if you cruise 7.5 miles per hour you can cruise a 68 miles one day and take the next two days for enjoying the sights. Cruising every day would be too tiresome in my opinion.
I hope this doesn't dissuade you from the trip, as it is a great once in a lifetime adventure.