In a similar vein, I absolutely love John Candy's last film, Canadian Bacon. Every time I rewatch it I go "man I forgot how funny that film is!"

Checking rotten tomatos its not quite as badly panned as Wagons East! (0% critics / 33% audience vs 17% critics / 52% audience) but seems like a good candidate for this thread nonetheless

Brief synopsis:

The president of the United States has successfully ended every war the country is involved in and is facing abysmal odds of re-election, so his team decides to start a second cold war, this time against Canada. John Candy plays a former weapons factory employee now sheriffs deputy in Niagara Falls NY, laid off with his friends due to the plant closure, and seeing the propaganda, they decide sneak across the border to stir trouble in Canada, losing one of their team who's caught and taken for a free mental health evaluation in Ottawa, so now they must take a trans-canadian road trip to "save" her