We appreciate the challenging nature of this situation.
It is illegal and potentially dangerous to immerse when required to be in
quarantine. These rules and regulations are in place for a reason, and help ensure the safety of all the women who use the mikveh. Halacha requires us to follow local laws and to take precautions for health. Therefore, you absolutely should not immerse when you are in quarantine.
Though safety measures at the mikveh are designed to keep women safe even if an asymptomatic carrier of Covid-19 immerses unawares, we need to try to keep those numbers down to a minimum, in order to minimize risk — and that means not having women in quarantine immerse.
If your husband is with you abroad, you might consider delaying your trip back to Israel by a few days so that you can immerse before returning. Another possibility would be to discuss with your physician the possibility of using hormones to
delay your next period so that you don’t become
niddah again close to when you come out of quarantine. Otherwise, you and your husband will need to be patient, knowing that you are acting for the public good.