We've stayed in Ghemme twice at Il Cavenago. It's a lovely setting, with heavy oak dominated rooms, a wonderfully peaceful grassed courtyard (with mesmerising bats doing their aerobatics at dusk), and a very good restaurant (but usually only open for food on weekends - unless there's a private party, in which case guests are also able to eat in the quieter section). The food is a typical agriturismo mini banquet, and they have sample menus on the site, and again typical, there's plenty of it. Highlight is often the risotto, and their basil risotto was the best risotto I've had, especially as it sounded like it shouldn't work / remain interesting through eating it all. Produce is either home-grown, or from local producers and that goes for the wine list (and there's even a Cavenago single vineyard wine by the lovely people at Miru (they may not be the peak of quality, but were truly wonderful to visit - Marco Aulunno runs the winery in the family home in town). There are bikes that are free to hire, but the gears had long since stopped working, but maybe they've been replaced / fixed. Some good cycle / walking routes directly linked to the estate.
Ghemme itself is remarkably bland, with a criss-cross of roads, yet few cars (the by-pass and nearby autostrada have taken the traffic away), so whilst not picturesque, it's pleasant to stroll around. A small historic centre worth a look, but not much that might interest a tourist, but we like that as it feels more embedded in the culture. A special mention to the lady in the Gelateria who gave the impression of thinking she had the best job in the world, and overall we found the locals friendly. 2-3 restaurants, none fancy can easily cover the other nights when Il Cavenago aren't cooking. One mention for Il Gufo Nero (the black owl IIRC) which is a solid functional trattoria, but I'd heartily recommend the braised donkey, which I (surprisingly) loved. Perhaps in hindsight it was a little hypocritical to pat the donkey at Il Cavenago when we returned there after the meal
There's also a place a mile or two along at Sizzano, called Impero. Faded elegance was the vibe, but enjoyably so.
Gattinara definitely more visually appealing / more to do / see, but we've not stayed there. We've driven there, but also cycled from Il Cavenago. There's a regional enoteca, but in terms of wineries, Antoniolo remain our favourite. Not cheap, but there's quality and a genuine seriousness about what they do.
I'll also put in a word for Novara, which I think is a lovely small city, spacious and pleasing to walk around, with a calm air about it. There are direct buses from Ghemme, but also a train service.