I don't remember if I ever posted what I ended up doing. I added a new cell phone line to an exisiting AT&T account, then AT&T ported the land line number to the new phone.
FYI, how I did it for free.......
I bought an AT&T Go phone for $29 that had more than enough features. I was told you have to buy a phone from AT&T, and have been happy with them for 20+ years, so I didn't shop around.
Called the toll-free number in the Go phone package and got a number assigned. If you're going to add the phone to your AT&T account, don't pay anything to the Go phone people. You just need the number - no air time.
Took the Go phone to the AT&T store, they added a different SIM car, asigned a new number and activated it. No cost for any of this. Don't ask them about porting the land line.
Get your land line bill and call 611 from the new phone and have them port the land line number to it. When they go to get the Verizon (or whatever line company) on the phone, tell them you want to be part of that conversation. Get the Verizon rep's name, ID and location. I had Verizon and they tried to assign me a new number and keep the service going. They are creepy.
It took 4 days for the new cell to have the new number active. Land line should be dead by the next day.
Also, creepy Verizon sends a tech over to try and disconnect all the wiring from the house. Don't let them in the yard! I have heard from neighbors who switched to cable, that they something disconnect the cable. Personally, I did not want the phone line sending me any signals "accidentaly" to the interconnection box at my house, so I disconnected it myself.