I'm not sure, but the size of the lens (exclusive of the Canon case) seems to be within size limits for carry-on luggage (I took a look at Southwest Airlines, which tends to fly smaller jets). Is your concern because you may be traveling on smaller, regional carriers?
Personally I would not subject camera gear to the tender mercies of checked-in luggage. All checked luggage must be unlocked (the TSA will break locks if necessary to inspect), and between the danger of being stolen or damaged due to rough handling, it just doesn't seem worth it.
The only piece of equipment I will check in is my tripod (Gitzo 1348), which rides in a large duffel padded by clothing. Even then I remove the ball head which goes into my photo backpack.