Given that there were guys selling tickets as we walked to our seats on race day, I'd say you have 18 weeks, 1 day, 19 hours and 18 minutes. Give or take. But I would say you could buy tickets even a couple of weeks before the race... getting them directly from the track, I would guesstimate you'd have to get them at least 3-4 weeks in advance, but earlier is better, especially if you want to get some of the better grandstands. Last year we drove up, not too bad of a drive. I have family in downtown Montreal, so I stay at a hotel and we drive to their house so we can park in their driveway, and then we walk over to the metro. If you're going, you would be welcome to come along with us, either on the drive up and/or to the track each day.