The prescription toothpaste they give you for tooth sensitivity really works but make sure you like the flavor you pick because you need to skip rinsing after you brush to for it to have time to sink in.
Totally worth it to be able to bite into whatever food you want without waiting for it to come to near room temperature.
It will make the air behind your fridge warmer in exchange for making the air around your body cooler. There’s usually not great airflow behind the fridge so it won’t affect the rest of your house much.
If you’ve got an open kitchen or something you can still freeze the bottles at night and use them during the day.