This should hopefully be a quick question. My wife and I were planning a trip up to Vermont, with a one night stop in VT. The hope would be to pick up some beer at HF on Thursday, be in Montreal Friday -> Monday then drive back Monday morning. My question is about customs. If I have 2-5 cases of beer in the car, that I purchased in VT, and plan to essentially leave in my car, are they going to give me a hard time about it? I have a cousin near Burlington who could potentially serve as a storage locker if need be.
I'd leave it with your cousin. They probably won't give you a hard time, but they certainly could. The limit to transport across the border is around 24 cans/bottles. Since you'll need to cross the border twice (coming and going), you'll have two chances to get hassled about it -- by either the Canadians or the Americans. Plus, here's a pro tip: When you're in Montreal, do yourself a favor and buy a BUNCH of Dieu Du Ciel Peche Mortel. It's an amazing beer and it's insanely cheap if you buy it in Canada. (You can buy it in 6-packs in most grocery stores and convenience stores.)
You would be better leaving it with yor cousin. The border agents on both side are becoming more attentive to the volume of beer crossing the border. They would question why someone from MA would be bringing a volume of beer into Canada. Even though your story is legit, it may cause you difficulties.
we got a piece of advice from a canadian we talked to during a HF trip, the one point he was very clear about is you have to declare everything however small. If they find you lie at all they basically black list you for any future. That would mean you would pay duty going in and duty going out. I am not suggesting you would lie but I am saying taking beer with you would end up costing you just to have it with you. I agree with the others park your beer in VT.
I've brought beer both ways there as recently as last winter and never been bothered. But if you have the ability to drop in Burlington, it'll be less anxiety at least, so why not. Also, taking nothing away from DDC, here are some other great Quebecois breweries in case you wander through a bottle shop: Le Trou du Diable, Les Trois Mousquetaires, Microbrasserie Charlevoix, McAuslan (Oatmeal Stout, RIS).
Good advice... never lie to a customs agent unless you enjoy cavity searches. You might get away with it but it really sucks if you don't. Just be honest. They will usually waive the duty for small quantities like a case or two because the paperwork isn't worth their time, but no guarantees. They can demand duty on everything in excess of one liter, so keep your Canadian beer receipts in case they want to see them.