Interesting situation you have developed with the USA - Canada war.
When it started - or rather when you started writing it - it was obvious that it would be a hard campaign but the USA would ultimately win
Now the story has taken over and is developing into looking like a race between CW build up and USA Build up resulting in a WW1 style front - with a side order of will US Public opinion starting to slide towards the 'why are we doing this again?' camp, if not for the heavy casaulties and fighting happening on US Soil but also the erosion of established and historical freedoms with the inclusion of checkpoints and IDs etc - which may result in serious pressure on the USA Government to end the war (with a Status quo ante bellum style peace).
Well done
Lol once again an example of the timeline refusing to go where I wanted it to.
But this war will be hard. The CW never really experienced the horrors of trench warfare. They also will be under huge pressure as the body count starts to climb.