Most cable providers are no longer using TiVo based boxes in their system so u can't get them back. Only option would be to get a regular retail TiVo. However, u would also need to get a cable card for a retail TiVO to use with with your cable company. From my understanding, Optimum is one of the cable TV providers who is also no longer supporting or issuing cable cards (since FCC dropped its mandate) so you can't go this route either. I think you are basically out of luck to get TiVo back in your area.
I have a Roamio & am with Xfinity. While they supposedly still support cable cards, I'm not sure how much longer & this is the similar reason I stay with them. I may be able to get a better "deal", but don't want to switch my plan (& maybe have to use their junk equipment) in fear of losing TiVO forever; even if there are probably better options out there. In my opinion, the Tivo experience really is still the best DVR user experience. unfortunately, its dying a slow death here. Will probably pick up steam here as more cable companies continue to not allow new subscribers obtain cable cards. Sad!!