Canada dwarfs Mexico: about 9,872,102 km² km² against 1,962,279 km² km². At true size Canada is about 5× larger — the whole of Mexico fits into Canada roughly 5 times.
Both sit in North America, so this is a same-region comparison: the new Equal Earth map draws both with the same honest geometry, and the real gap is exactly the 5× you see above.
The old map muddied it further: Mercator inflates Canada about 4.1× and Mexico about 1.2×, so on a Mercator-style map this pair appears 17.2× apart instead of the true 5×.
Mexico fits 5× into Canada.