We have a halachic obligation to follow the instructions of Israel’s Ministry of Health and to prevent a situation of possibly endangering other’s lives.
Women who are in quarantine for potential exposure to the Coronavirus are prohibited medically and halachically from leaving their homes. That precludes immersion in a mikveh, which could potentially endanger other women, even if the woman in quarantine plans to immerse last.
If you must delay mikveh immersion, please complete your clean days as planned. After the clean days, you need not perform any more bedikot, and you should switch to colored undergarments.