We usually hunt moose in mid-late Oct. on the west side of the Rockies and a bit north of where you're going - below Jasper Nat'l Park. Our experience is that a bout of cold weather does help get the moose moving. If we catch a bit of milder weather it can be pretty hard going, but as soon as it's snowing in the mountains and cooling down in the valleys, we start seeing more moose. It doesn't have to get below freezing for this - but then the weather's milder on the BC side than on the Alberta side, so there really isn't a direct comparison temperature-wise - but there does have to be a cooling trend and some nastier weather. Moose behave a lot like blacktail deer: they will stay at home in good weather and move around more when the weather is inclement. Nothing like hunting them in a cold rain or snow. Now, in severe, stormy weather with high winds, they hunker down.
We just came back from a hunt in that area, and if the moose are behaving the same way on your side of the mountains as they were on our side, you're in for a good hunt. We saw more moose in our four days of hunting than we usually do - and got a young bull on the first day out.
