I posted over on your other thread- so hi again! Just a heads up, you might not be allowed to bring your canned salmon through customs, although to memory the US tends to be more strict about "meat"... then again, Vienna was the easiest security/customs experience ever, we basically just walked out so probably no one would notice anyway even if there is a law about it.
If you have a chance you can stock up at grocery stores and health food stores in Germany. Also, if you're doing the crazed bus on the autobahn thing, Landzeit autobahn restaurants have awesome salad bars that are more like deli counters- variety will vary on the place, but the best one had a really posh seafood etc. salad counter as well as veggie salad counters.
http://www.landzeit.at/ I'm not sure if they're just an Austrian thing or are also in Germany. Other autobahn restaurants may have equally good salad bars, and may have plain hot dogs or meats- you probably want to research your "wurst" before you go to find safe varieties, so you may not be completely starving. Good to have backup though, definitely! You can always have soda, water, high calorie coffee drinks and schnapps if you're into that sort of thing. Oh, and Gluwein should be gluten-free. You may have luck with Rosti potato "hash browns" as well- I found them made fresh and with just potatoes.
Enjoy and I hope this helps a little!
-sea
from the www.bookofyum.com
PS it would be great if sauces were all thickened with potato starch- the Celiac society led me to believe that they wouldn't be, so be really careful about this. I was very paranoid my entire trip about sauces, which makes it tricky when almost everything comes with a sauce. lol. Definitely bring dining cards in German if you can!