Before Maria, ATT cell was good over the entire island. Since then recovery is slow but improving. My friends had new direct tv and internet post storm. Seems ok.
I will stick with ATT till we return, don’t know what will be available then.
I have a couple of at@t phones here I used to carry on at@t one Verizon and a sprint phone everywhere I went the providers gave me one I have a few extra phone here if any one wants any they are the iPhone 5s sprint or at@t
Service is still spotty but it should normalice in the next 3-6 months. If you have the money for a satphone and the monthly payments, that is great but you are not likely to need it often.
I don't think you'd need a sat phone unless you are planning to stay somewhere in a remote part in the middle of the island. Cell service has been restored to at least 90% of normal with AT&T almost up to 100% of the pre-hurricane coverage level. I'd suggest to take your phone(s). I'd be surprised to hear you will have connectivity problems.