Lake City, about 15 min. from Cadillac, has some activities over the 4th. See this link:
Lake City Area Chamber of Commerce
And here is a link to Local Edition, covering local events in the Cadillac & TC areas:
78 Year Old Learns to Fly at Local Edition
google canoe rental Cadillac, MI. There are a few in the area. Lakes Cadillac & Mitchell are nice to drive around, bike around, or boat in. There is a nice swimming beach, Kenwood, at Lake Cadillac. Another nice swimming area on Lake Missaukee in Lake City. Hopefully the weather improves in time for all these ideas!!!