An ultrawide like the Canon 10-22mm plus a 50mm prime (short tele on APS-C) does leave you without a 'normal' lens - maybe that's ok, but I'd be tempted to bring the 18-55mm. As long as you have ready access to your friend's 100-400, leaving the 70-200/4 behind makes sense. But you'll want a telephoto lens along, IMO.

People associate wide angle lenses with landscapes, but many times it's very effective to be able to isolate elements of a landscape. Also, if you've never used an ultrawide lens, they take thought and planning to make the most of them. Just shooting a wide shot to capture the majesty of a scenic vista almost always produces disappointing results that don't measure up to your memory. Instead, have a very close subject in the frame to draw the eye into the image.

I know you asked about lenses, but also be sure you have a decent tripod!