Bob Michaels
nobody special
The "one body, one lens, no backup" is also a personal thing. If you are going on vacation where the vacation aspect is primary and photography is secondary you can live with an equipment malfunction. But if photography is the main reason you are going, don't risk being somewhere remote for an extended time period with no functioning camera.
Clarification: when I travel to photograph, I leave every morning with just one body, one lens, pocket full of film and use it all day. The backup body and lens stays somewhere secure where I am staying at night. The backup almost always never gets unpacked.