Not only depending on traffic and time of day, it also depends when Port Alcan decides on additional screening measures at random....
Although the last three entries returning to Alaska at Port Alcan for me have been pleasant, the other twenty or so times prior not so much as it seemed the majority of non Alaskans were cleared in a more timely manner as I end up in secondary or hang with the other Alaskans waiting to get cleared or getting panty searched at random.
Beaver Creek station at Canada Customs as noted can have traffic waiting, as generally they will clear me between three minutes to forty minutes depending on what they are dealing with and their workload.
Generally returning to Alaska at the Boundary-Poker Creek joint US-Canada station, it was a sneeze and a scan of the passport for me, as the CBSA officials there when entering Canada takes me anywhere from 5 to 40 minutes to clear with them, with or without traffic.
Bottom line is it will not be as daunting upon crossing the main port of entries along the continental US border with all the much busier traffic that is there.
1975 Ford F250 2WD Ranger XLT (Owned June 2013)
460 V8- C6 Trans- 3.73:1 (196K Total Mi)
2000 Fleetwood Angler 8ft Cabover
Air Lift 1000 (Front)
Hellwig 3500 lb Helper Springs (rear)
Hellwig Front and Rear Sway Bars
Goodyear G971 LT Series (siped)