Sling would be the cheapest, it works well but you will need multiple devices with wired ethernet or wi-fi. For your situation plug the cord back in for now and revisit later on. I say this as a person running a Tivo Bolt OTA, a Roku, and an Apple TV who's used Sling Tv and ATT TV Now. A lot of cord cutting is really cord shaving and I've put up with things that would drive most people crazy. Beware the candy coated "cord cutting" bias on the internet. Reality is a bit more complicated.
Since you have the investment in the equipment go back to Fios for now. Your household will be happier for it.
Revisit in a year, a lot can change in 12 months.
Since you have the investment in the equipment go back to Fios for now. Your household will be happier for it.