Evap emissions canister plugged - OK to drive?

[Racer-X]

Ok here's the deal. I went through a really deep mud bog a couple weeks ago (stupid I know, but it looked like so much fun ). A few days later I get a check engine light. Onstar says evap emmisions failure.

Well the dealer just called and said the evap can was plugged with mud - it all needs to be changed out, but they don't have parts and it won't be fixed until friday.

I told them I have a off-road trip this weekend, I need to leave thursday. They said it would be fine to drive it, it won't hurt anything. Take it and bring it back monday.

Anybody disagree with that?