If you were dead serious (excuse the pun) then a full cage into a reinforced chasis would be the best option from my limited knowledge... (even this is far from perfect)
All that said, the cost and practicalities of doing both are not economical for the majority. For most of us we just don't think about it and put it to the back of our minds and hope that we don't ever get tangled up in that way. It's a hazard with running vehicles of this vintage or earlier.... Nothing is imune, advancements in safety over the last 20 years really do show though!
I certainly wouldn't go on any kind of drive or spirited one at that if I stopped and thought about the consequences. Life's too short as it is, live in the here and now I say.