If I could fill a 4MB card in a race weekend (Mid-Ohio ALMS and IRL)....Europe would be 5 X that!
I filled 3 2MB cards in 5 days at Yellowstone. But I made a trip to Wal-Mart to burn DVD. I also back up nightly on my laptop.
So, I back up nightly....Burn everything to DVD and still not erase cards till I get home and copy to my PC.
I have 3 external hard drives ..one, I keep in safe deposit box. DVDs are kept at my kid's house.