questions re on-line delivery of "Wood Burning Stoves 2.0"

I'd like to buy "Wood Burning Stoves 2.0"

If I buy the physical DVD's then I must pay customs to import into UK, and there's the CO2 emissions of shipping them to me.


I see I can stream them - can I stream as many times as I want? and is that for ALL the devices I have?

Can I download them and store them on my local hard drive?
If so: How many megabytes is it in total - I don't want to run out of space!!