Aberdeenshire to Portsmouth. M6 stops?

[Storm28]

We're heading to the ferry at Portsmouth driving from Aberdeenshire, 10.5 hour drive (thats with no stops) with 3 boys age 4 - 13! We've done long drives to England before but this will be the furthest. Hoping for recommendations for things to do along the way that don't involve going far off the motorway as we don't have time to waste. Ideally play parks or certainly outdoor places for them to run about (ideally free as we won't be there long). Kids love things like castle ruins etc. although I imagine have to pay for this type of thing down south. Probably looking for a couple stops. Thanks in advance

Yorkshire sculpture park does cost but I think kids might be free. V close to motorway but great place to run about a bit and has cafe toilets etc.

To enter the parkland at Tatton Park, and access the trails, picnic areas, toilets, adventure playground and cafe, you only have to pay for parking. It’s only a few miles from junction 19.
No more than a mile from junction 22, there’s Kenyon Hall Farm which has a play area and walking trails. https://www.kenyonhall.co.uk/winter-welly-walks-162014.html
Brockholes Nature Reserve is at junction 31. All the usual facilities, plus a play area. You only have to pay parking.

Tebay services has a walk from it.

Pay for the toll, it’s worth it.

Camperdown at Dundee is probably too early, but works well.

The Phantom Winger pub at Preston North is a Hungry Horse (so cheap, Dyce Farm style pub) and has good indoor and outdoor play area. Couple of minutes off M6 but in a business park not a services.