This is starting to sound like it's almost better to just stay home!
Cards can and do fail -- I think in the 13 years that I've been shooting digital, and using about 10 different cameras and about 50+ cards of all sizes and brands, I've had all of two fail (one CF and one SD). Even with the SD that failed, I was shooting both RAW and JPEG Fine at the time, and I was able to recover the JPEGS by putting the card in another camera and transferring the shots from that camera to my computer (and I thnk I could have recovered the RAW files if I worked hard enough on it). The CF card failed after only taking about 4 shots, so I didn't really lose much of anything. And I had been using that card for about 3 years up until that point.
Here again, I'm coming at it strictly from a vacation standpoint. One of the issues we had on our recent trip (Arizona/New Mexico) was that we were traveling in an Airstream trailer and a Chevy Suburban, so no hotel, no safe, not much security, and sometimes no amenities (no electricity and certainly no internet). So we had enough other stuff to worry about.