I don’t think you can compare riding in the Alps for a week with regular UK riding as you do consecutive long days of riding. The more tired you get the more likely to mess up you are and then your pads become your friends. If you are thinking having “just one go” the DH runs they a FF and some goggles and knee protection are invaulable, if you intend to ride multiple DH runs then all the normal DH protection applies!
Last time I went out there all the local ripper kids just wore neck braces, FF and maybe knee pads. They were about 12, bounced on impact and were very good riders! I do not fall into any of those catagories so wore all my armour. I was only riding DH so didn’t feel foolish and when I did fall off I got up again. Its up to you really but being on holiday in such a great riding venue will make you want to try bigger and dafter things, you just cannot help it and it doesn’t take much to have an off. I’d take every bit of padding you have to be honest!