Just go to Roxham road at the Quebec border walk across and you will be welcomed fead taken to a hotel given some money and a cell phone if you don't have one.If really want to go you can apply for Criminal Rehabilitation with the Canadian government. That would allow you to enter Canada with a DUI. But as most things are it cost money.
Then you can go do anything.
Why bother with the real border crossings,they are a PITA