I use Verizon. On days that I want/need service, I use Verizon's TravelPass. Just fire-up the phone, and it works. When activated, I get a text saying that the phone is good for 24 hours. About an hour before the period is set to expire, I get a reminder text to either go to airplane mode, power off, or be charged again. Works on both sides of the island.

The charge is $10/day with the same talk/text limitations as my plan at home. Good enough for me.