Do you mean the Berlin Airlift of 1948-9?
Yes. I got my dates mixed up. The military can fly in a lot of cargo in a emergency.
Read? Do you mean access?
However, the Vancouver area shouldn’t be among them. Farther inland, or at higher altitude, definitely so.
An airlift will, of course, require proper personnel which they may not have right now.
Well, the roads are hard to read when they’re covered with snow. 
(I assumed he meant ‘reach’.)
I think the RCAF has 17 C 130s, with none stationed in BC or Newfoundland. I get that airplanes are mobile, there, but it’s not clear how many planes could deliver how much cargo in a timely fashion, given the infrastructure of the RCAF and the state of the roads. I hope we don’t have to find out.
I meant to write “reach”.
I would say it’s the opposite - melting conditions may make a road impassible, but cold and snow just need plows. In Spring, there are “road bans” that mandate a reduction in vehicle weights because the frost is coming out of the ground making the road unstable. And the are also ice roads across lakes that only operate in the winter.
Where do you live? Here, they close roads (e.g., WA 20) for Winter and open them when the snow melts.
The subject line reminds me of back in '96 when Portland was cut off by road from the rest of the country. Portland is not as hemmed in by mountains as Vancouver, so it required no less than 5* landslides/floods to do the job. Technically, Portland wasn’t totally cut off, since the highways to the west were still open as far as I know. But the roads to the west only go to the coast, which is a nice area, but not one of the main ways you, and more importantly, goods get to/from Portland.
*At least 5. There likely were more.
Alberta. Some of the Provincial and National Parks are seasonal, but I’ve never heard of seasonal highways except for the ice roads in the Northwest Territories.
Some mountain roads get a LOT of snow – it is interesting to see when they start removing snow from Going-to-the-Sun road in Glacier NP. There is ~10 feet of it. Granted that is over the season, and maybe it could be plowed daily, but there really isn’t enough traffic to justify. H58 in Michigan’s UP isn’t plowed in the winter and becomes a snowmobile trail.
Brian