Eliminate Cable Box

I presently have the DVR box on our main Samsung TV. I have two additional TVs and use boxes on them. The main TV is a smart TV but the Streaming App will not work on it. The other 2 are older TV’s so no App there either.

Can I use Roku on both of the older TV’s and stream from the main TV that has the DVR box on it. I am trying to eliminate the 2 boxes and save some $ or could I drop the DVR box and replace it with Roku and still have recording capability?