PBS addon fully buffer (or save to file)

(This has most likely been asked/answered before, but I couldn't find any relevant answer.)

I am using the PBS video addon to watch some of their shows. But sometimes my network gets clogged with a lot of other traffic, and the show stops to buffer more. I am wondering if it is possible to buffer the entire show for playback later. or even save the show somewhere on my disc.

Yes, I know there are copyright issues with saving shows. But is it possible to at least do a complete buffering before playback?

TIA

ken