This is indeed a strange war. Both sides claim the other side started it. Both claim to have won the war.

The British/Canadian take was that the Americans wanted to conquer Upper and Lower Canada, with eyes on the Maritime provinces for later. In other words, the War of 1812 was the start of Manifest Destiny.

The Quebecois (Lower Canada) were sitting on the fence, holding meetings with American envoys. Some historians believed the Quebecois were hoping for an American victory, so they could declare their own independence from the British. But if the American army was too strong, that independence was not likely.

On Medium, there are many critics of the Electoral College. Yet it was the Electoral College that had a big impact on the final battle of Fort Detroit. Had the British been able to amass a couple hundred more soldiers to that battle, Michigan and states west of Michigan would be in Canadian hands today.

https://medium.com/politically-speaking/abolishing-the-electoral-college-83ff9ce24a6c

One result of the war was that the British were realizing the difficulties of governing lands far away, especially when the people were not exactly supportive of British rule. Both Upper and Lower Canada had their mini-revolts in the 1830s. These two regions, coupled with New Brunswick, Nova Scotia, and Prince Edward Island were continously meeting with each other to form an independent nation. Eventually Britain allowed this united front to go its own way in 1867--without any war.