You might want to contact the hotel and let them know you will need a special diet and make sure they can accommodate your needs. Another option is find a hotel that has cooking facilities (at least a microwave) and prepare your own food, or at least part of it.
I must stay 4 days at the hotel for studies and blood tests prior to treatment, so necessary to get food in the hotel of the low iodine diet.
Once you are dosed, you will not have to follow the low iodine diet, at least that is my understanding. Your thyroid will take up all the RAI in the first 8 hours or so, then you should be able to resume a normal diet. Ask your doctor, that is what my doctor told me.