Perhaps it's a personal account or a fictional story that revolves around Ontario. It could be about the everyday life in Ontario that is filled with so many different aspects such as different seasons each bringing their own set of activities and stories, various cultural festivals, and the interactions between different communities. The 'never - ending' part might imply that there are always new things to discover, new relationships to form, and new events to happen in Ontario, so the story just keeps on going.
I'm not entirely sure specifically what the 'Stratford, Ontario, Never Ending Story' is. It could potentially be a local legend or a creative project unique to Stratford, Ontario. Maybe it's a story that has been passed down in the community for generations and keeps evolving, thus the 'never ending' aspect.