Andrew Sarangan wrote:

The enroute chart for the border states include a significant portion of
Canada. Is this sufficient for IFR into Canada? The VFR sectional contains
a warning that the airspace classification may be different in Canada and
that the pilot should consult the Canadian Flight Supplement. But the IFR
charts does not say anything.

When you are flying airways under IFR airspace classification differences are
a lot less important than when flying VFR. The VFR charts are valid, but the
note cautions the VFR pilot that the airspace classifications used in the U.S.
cannot be assumed for Canada.