Just before the boxer there's a great area with several campsites. William has a great beach, but no service, Adam Lake has full service and a great campground. If you have little ones, Souris and Wawanesa have fantastic pool amenities. I know Souris is full service but not sure about Wawanesa, haven't camped there, too close to home lol.
Also look at Pelican Lake by Ninette. There's a great seasonal place there called The Lookout