Sorry, you booked a tour on December 25?? Are you certain? I would doubt they would be operating on Christmas day.
According to the Viator confirmation, yes, 8:30 on the 25th - I was surprised too. Perhaps since it's a busy tourist week, people are working.
As for grocery stores, probably Carrefour by Mark's would be your best bet. HOWEVER, I would caution you that you may want to re-think stopping on the way from the airport to get groceries. It is NOT advisable for you to leave your luggage, etc in your car and go grocery shopping, unless you have someone sit in the car. This should be a theme for your whole trip--do not leave ANYTHING in your car, at ANY TIME, for any length of time, at ANY place. If you do, it may be stolen. I believe there is a really small grocery store at the hotel that you can pick up a few things. Alternatively, you can contact one of the grocery provisioning services and get some first day supplies delivered to your room, then do a big grocery shop the next day. OR go to the hotel and drop off your bags and come back to the grocery store.
Appreciate the safety tips, will definitely keep that in mind!
