Contract term for ported land line number?


Planning to cut the cable with Spectrum, but would like to keep my old land line number. I know I can port it to Verizon, and I have a spare old iphone 6 that still works and can use it for this purpose. Here's my question: I only need access to that number for a short time. When I finally cancel it, will I be hit with an early termination fee? is there a contract term for this sort of line being added to my Unlimited plan? Thanks