Would really recommend staying at Carla & Ivan's place! The view is just as it looks in the pictures - even in February! We can only imagine how beautiful it must be in the summer. Hopefully we'll find out one day!
Their place is clean, spacious and peaceful. It's also within walking distance of a couple of local shops and restaurants (and the lake). It's only about an hour's walk to Lovere too, which is a lovely town. The walk does take you along the road, but there's more joggers and cyclists than there are cars!
The locals in Riva di Solto were all very welcoming and friendly; everybody says hello.
There's also a nice walk from Riva di Solto, up an old mule track to a panoramic view and through some old villages with cobbled streets. It's referred to as a "nature trail" and also as a "moderate hike", but we'd describe it more as just a pleasant walk around the local area! There's some really nice views along the way.
Activities-wise, you're probably better off hiring a car when staying in Riva di Solto. There aren't many buses and the ferries don't go from there during the winter months, so it can be a little tricky getting around. We did manage by bus and on foot though! And Carla & Ivan are always there to ask for advice; they're both very helpful.
We'd definitely stay there again!