Really. Whilst health insurance can be an issue with age, I've never seen age a factor with travel insurance.
Most ??FREE?? travel med insurance that comes with Amex/Visa/Mastercard is typically age restricted....if you buy to cover yourself then thats on you not them.
Here...
https://www.rewardscanada.ca/medicalinsurance.html
...but this Canada so other jurisdictions might vary...