Is it legal to take unopened liquor into Canada from the U.S. ?

why not?

Even opened is OK so long as it's not in your lap and on your breath as you drive in.

As long as you meet the age requirements set by the province or territory where you enter Canada,<BR>you can include duty and tax free one of the following: up to 1.5 litres of wine, or 1.14 litres of liquor, or 24 × 355 ml cans or bottles (8.5 litres) of beer or ale. You can bring more, up to limits set by the various provincial liquor authorities, by paying the appropriate duties and sales taxes.

ron is correct. However, we've stopped at the duty free shop on the way and picked up more (they do have terrific specials), which we've always declared (they ask and you can or not) and always been waved right through. Prices are probably better at the duty free shop just ahead of the border than whatever you bring from home. Be advised, that you are also expected to declare any unconsumed liquor when coming home. Again, if we haven't consumed our supply, we always declare it, and have always been waved through. Those allowances, it would seem, are more to prevent "reselling" that collecting duty on quantities for your personal consumption.