I will give an example using a completely different format.
You can take a small .mp3 & convert it to a .wav with conversion software.
The .wav will be much larger.
If your television could play the .mp4 from a DVD it would be a lot better quality that converting it to DVD format that will fit on a single layer disc.
If you are going to convert this .mp4 to DVD format I suggest you burn it to a dual layer disc. or split it & put it on two SL discs.
My TV has a USB in that I can plug an external hard drive into. I know it can play .mkv files this way & I think I tested .mp4. I will have to test again to make sure.
So if you are going to be using .mp4 format it might be good to get a TV that will play from an external hard drive via USB.