Tax/Insurance for day of collection

I am about to purchase a second hand car, which I will need to go and collect some 70 miles away and bring back. The car has a current MOT so it's road legal, but won't have tax or insurance on it. It's a repossession auction, so I'm conscious there may be some work needed, so I plan to have it SORN for the first few weeks.

I don't want to get in trouble for driving the car home without tax and insurance, so wanted to check the best method.

Thanks