Thank you for reaching out to us.
1. In this case, as you suggest, you would do your main
preparations on Sunday. Then, at the mikveh in Israel, you would be able to refresh your preparations fairly quickly – showering, combing your hair, cleaning your teeth, and checking yourself for
chatzitzot just prior to immersion.
2. Yes, a fresh gel manicure and pedicure from Sunday should usually be in good enough shape for an immersion over the next few days. Learn more about the halachot of nails and mikveh
here.
If you are able to immerse upon arrival, that could be wonderful, and enable you to be out of
niddah from the very beginning of your trip. If, however, you are too tired to make it work, you and your husband can agree to
delay immersion to Tuesday night.
Wishing you a successful trip! Please let us know if we can be of further assistance.