Digital expose for the highlights. Film expose for the shadows. For best high ISO digital shots, make sure to not underexpose otherwise you’ll end up with more noise. So with this said it can be challenging in situations like you have shown. Lucky for you the R5 has very good high ISO performance don’t be afraid to use it! Also maybe try in camera HDR for shot like this one. I shot at the mill 11 years ago with a Canon 60D fitted with EF-S 17-55 highest ISO that day was 1600. I was very satisfied. One other thing when in this situation with high dynamic range try and compose your shots with highlights in mind. I do my best to keep as many of them out of the shot as possible. I kept the majority of my compositions closer in and pointing down or away from outside light. Here are a few SOOC examples so they will look better once processed.