Hartleyburn Hall. It's big, sleeps eighteen across seven bedrooms with six bathrooms. It's in Halton Lea Gate, right on the border with Cumbria.
It used to be the village shop, that bit is the main kitchen and dining room now. There are two kitchens and a few living rooms, so people can spread out. It's got a 4 Star rating, so it's well-equipped. TVs in all the bedrooms.
There's a big games room and a hot tub in the garden. The garden wraps around the house, about half an acre. Kids' play area in the village.
A few things to note plainly: some of the stairs are steep and a bit narrow. They're original.
You're in the North Pennines Area of Outstanding Natural Beauty. The Pennine Way is just east of the village. Lots of footpaths and cycle routes straight from the door.
It's about twenty minutes to Alston, England's highest market town. Hadrian's Wall is maybe forty minutes north. RSPB Geltsdale is nearby for wildlife. Within an hour you can get to Carlisle, Hexham, or Newcastle for the city stuff.
The nearest shop, pub, or restaurant is four miles away in Alston, so you'll likely drive.
Facilities: wood burner, dishwasher, washing machine, BBQ, on-site parking. Bedding and towels are included. Cot, highchair, and stairgate there if you need them. No pets.
Useful links: North Pennines AONB and English Heritage Hadrian's Wall.