Most happily cross-posting with PianoWorld. Don't know which subforum this belongs to, really, but I guess Student's Corner will do:
Per Tengstrand has written an excellent blog posting about the Waldstein sonata with some lovely excerpts.
https://worldofbeethoven.com/op-53-waldstein/And just to make people like me even happier he launches a 75 minute seminar about how to play the Pastorale sonata.
https://vimeo.com/ondemand/pastoraloneThis is not free material but the price is really peanuts, especially if you consider what time it must take to produce such a video. I have not watched it myself yet but I love his earlier videos, they have been extremely useful to me. And no, I'm not an affiliate ...