Lucius Verus
Banned
That's a bit of an exaggeration; they quite famously failed to take Baltimore (to say nothing of New Orleans) when they tried, and other cities have similar fortifications. And of course, the British would have to actually be sufficiently interested in such a campaign to do so; Canada is not that important.
But a major American victory probably requires the Napoleonic Wars to go on longer, anyway.
Canada was seen as a secure source of timber for the Empire, which was seen especially after Napoleon's attempt to block-aid Scandinavian timber vital to the supremacy of the royal navy and the isle's security.