IRCC can you travel soon email

COPR expired in 2020, we were unable to travel due to COVID lockdowns. IRCC emailed this week that they’ve extended the validity of the medical exams to July this year and asking us to confirm if we can travel by then. Currently we are not in a position to travel as that would mean voiding our pending i485 application in the US. We were hoping to permanently immigrate to Canada in 2 years time.

Given the circumstances, if we do not respond to this email or respond that we are unable to travel within July, will we be allowed to get our COPR stamped at a later date? Paying for new medical evaluation after july is not a problem.

Should we proceed with caution and consider this our last chance to immigrate?