About the only activity in Peyrieu is walking, either head east from the village and walk along the rhone, or head west onto the mountain and walk along the GR (national hiking path) wherever it takes you. I strongly recommend getting a good hiking map for alternative routes although the GR is well marked with red and white flashes.
I didn't eat here although Sonia does do bar meals, mostly of the burger variety. But she is excellent company, great fun and is a huge fan of walking and instead of having a siesta like many she goes out walking - whatever the weather. She loves to discuss places to visit and walk to. As she already had a deep tan when I was there I think it must be year round for her. She also does B&B but you do need to speak French, she has a few words in English but not many.