I'm going to give my 2 weeks while my boss is backpacking through europe
Why are you going to do that then?
Because it is the last opportunity I have to quit my job
It sounds like you have the decency to give notice. Don't you want to be the type of person who's decent enough to avoid quitting while your boss is away, though?
I don't really know.
Think about it a bit. If you still want to make that choice, it is up to you.