Hallelujah - it covers Canada.
That elaborate design looks like a data pig. In remote areas (U.S. or Canada) that have very little cell signal, I doubt it would load, whether as URL or app content.
I'm not sure I'd survive, and I certainly would not do it sanely, without the Canadian federal government's radar pages. They are stripped-down, coarse-grained, 1990's-looking web design atrocities but they really work. They don't demand much data and they have just enough crude animation to show what's going on. Click / tap the black dot closest to your travel area (on my phone, I use the 8-color version):