My husband and I will be traveling into and out of Canada a number of times over the next couple of years (we are US citizens). Because we are full time this is our home and we have considerably more alcohol than we are allowed to take over the border duty free. Does anyone have any experience with this or know what kind of tax or duty they will impose on excess liquor? Or do we need to just try to get rid of it before crossing the border? Thanks for any help! 

Welcome to the forum!  Here's a site that may help.

https://www.ezbordercrossing.com/the-inspection-experience/clearing-customs/what-will-it-cost/

How much did you pay for the wine?  We normally carry a case or more of wine and price per bottle is usually $25 or more, so we don’t go into Canada as a rule.  Once in a while we will be down to around 4 bottles (before our trip down west coast in the fall) and then may go in.  

 
Quote

U.S. citizens crossing the border into Canada to visit are allowed to bring the following item quantities into Canada duty free:

• 1.5 liters of wine, or 1.14 liters (40 ounces) of liquor, or 24 cans or bottles of beer.
• 1 carton (200 cigarettes), up to 50 cigars, and 200g of loose tobacco
• Up to $60 in gifts per recipient. (excluding alcohol and tobacco)
• You can bring a “reasonable amount of perfume.
• There are no restrictions on cameras
• You can bring a “reasonable amount” of film
• You can bring gifts duty free so long as none exceed $60

You are not allowed to combine your personal exemptions with someone else or transfer them to another person.

For more information, try reading this page which is in layman's verbage.

Kirk, could you use those pages and tell how much per bottle of wine would be charged - 5%, 10%, 25% of purchase price because I couldn’t find it.  After all, that’s what the OP wants to know.   Prior years I have heard that the percentage can be over 50% of cost, which is why Canadians don’t stop at wineries on their way north to buy, just to taste.  

The cost is dependent on the province or territory you are entering Canada through. Instead of using a website like ezbordercrossing, go straight to the horse. Here's the official Canadian Border Services website, which states: " If the amount of alcohol you want to import exceeds your personal exemption, you will be required to pay the duty and taxes as well as any provincial or territorial levies that apply. Contact the appropriate provincial or territorial liquor control authority for more information beforeyou return to Canada." Some provinces and territories have Provincial Sales Taxes, which all vary. All charge the Federal Goods and Services (GST) tax, which is 5%.

IOW - there is no easy way to determine what it would cost to take wine with you.  As I said, that's one reason we never take the rig into BC anymore, we almost always have too much wine with us.

Go to Canada [BC] every year to visit family.  Have learned that for two of us, one big bottle of whiskey, and two regular bottles of wine are the max. Coming back to the states, no problems, probably because Canadian prices are crazy, so nobody would buy booze there to bring back to the states. Now will not talk about potatoes.