The hotel is holding the rooms and honoring our group rate until 30 days before the wedding. All rooms are first come, first served, so if there's a specific room category you want, you should reserve it in case it sells out.
We were able to walk there in about 25 minutes, but keep in mind there is a very steep hill to get there. Alternatively, it is an easy 5 minute cab ride and there is a taxi stand right outside the hotel and the valet can call a car over for you.
Currently (as of December 2021), the US requires a Covid PCR test taken 72 hours prior to departure. Proof of a negative test is required to board your plane back to the US. If you wish, the Thompson arranges for a nurse to come to the hotel to administer the test for approximately $30 USD. Alternatively, you can take the test at the airport, but there may be a wait. If the US Covid regulations change, we will update this answer.
Unless you plan on traveling to the further beaches (La Saladita, Troncones, etc.), you probably do not need a car. Everything is walkable or accessible via taxi and the area we are in is very safe. Downtown Zihua is a 5 minute cab or 25 minute walk from the hotel. If you do choose to rent a car, you can do so at the airport and the hotel has free overnight parking.