Probably we would see a stronger Native American presence in North American affairs in the 19th century. After the War of 1812, the Native Peoples, even acting in a coalition with each other were effectively done as a power that could temper European/American expansion westward.
I'd say they get an extra decade at best, they were on their last legs as a cohesive force as was prior to the war, without open war between Britain and the USA the Brits won't back them to the hilt and they ground down by demographics just like OTL, just at a different date and maybe a different Indian War.