To take DS out for the day in the countryside.

[DiaDino]

I live pretty close to a national park and i was wondering if I would be unreasonable to drive DS there, take a ball and go for a walk and a picnic in our car in light of all thats going on. We're not in self isolation, I just wondered if it would be classed as social distancing? I don't suppose many people will be using the area

As above. If socially distancing (so everybody who is not self isolating) you need to maintain 2 metres distance but there is nothing to stop you getting fresh air and exercise. If quarantining (either because you or a family member is symptomatic) then you need to stay home.

The above Government advice is for self isolation, not just social distancing.