Dear friend,
You are yet asking the same question under different garb. Plz note that once our Visas are issued, our medicals have no locus standii. That means of no value. Now, all we need to bother is about the Visa Expiry Date ONLY.
You must fly & land at your Port of Entry in Canada before the Visa Expires. Medical Expires or Not has no consequence, Nothing to Worry About.
I hope you understand the importance of the matter now...
I repeat: "Visa Vs Medicals" - Visa Expiry Date is important.
Regards.