Monkey Puzzle tree (Araucaria araucana) (Stanstead Abbotts SG12)

I have this tree growing in a large pot but it really needs to be planted out in a large garden where it can eventually achieve 12 metres height by 8 metres spread. I really don't have that space. Please note, it's quite prickly and also doesn't come with the pot so I will put it in a large, damp sack with a big football. It will need to go straight into the soil really.
It won't cope well with clay soil by the way.