How much space? 500kg, or 1000 lbs. A brown paper sack of potatoes is usually 15kg, which will have a similar density to apples. So 30 of these bags. It would fit in the back of my car which I will happily donate for the purpose, although you would probably have to drive it yourselves.
70 gallons is 35 2 gallon demijohns (even though OED says that a demijohn is from 3 to 10 gallons...) weighing about a third of a tonne.
Should take half a tonne & a driver - the latest Audi A6 has a payload of 550kg, I think mine might have a fraction more. Might be a bit short of capacity for passengers though. I haven't got a towbar, though.
For anyone who wants to learn more about making cider, the courses here might be of interest (the bloke in Cheam who hires presses told me about them. Apparently he used to help on the courses. It's in the Forest, Tharg, and sounds like an interesting place.)