DVR saved?

I'm being asked to upgrade my equipment for 4K stuff. I only need it for one TV, which is my main cable box in my living room because that's the only 4K TV, and I do a TON of recording shows, specials, and movies, many of which I cannot afford to lose because they were either final shows, new show beginnings, and one that's the history of Philadelphia, which I need for help with my family history. I have about 192 recordings, and 62% full. 

How can I guarantee that I don't lose these during that switch over? I will be VERY upset if that happens... I mean it's bad enough I'm paying extra for an entertainment package that is supposed to include the NFL Network and NFL RedZone and those two are not available... So imagine if I lost my DVR stuff on top of it.... I would definitely be spitting fire.

Reassurance that this won't happen, please?