Here's one way to get to Wadenhoe without going through Oundle. It includes about 1 km of bridleway, so think about your bike and the ground conditions, but it makes a change.
The route is 69 km, with the King's Head at Wadenhoe coming up after 36 km, or Café Oak at Geddington after 56 km.
Here are some routes that we regularly use for club runs. Use the Categories to limit the routes you see. The compass points relate to where the ride goes from the clubhouse. Routes can be downloaded for your cycle computer, either directly as a GPX or via Strava for TCX.