Anyway you could strap a motorcycle onto the truck?

I've seen a guy with a Freightliner cabover running I-10 in AZ-CA with it mounted in the front. It is more of a dual sport bike.

 

Depends on how much space between cab and 5th wheel I have seen sport bikes behind the cab on a hand full of trucks if your brave enough to ride up the ramp you can get what ever you want up there but if your pushing the bike up I would stay at like a 250 so

 

Yeah I've seen full sized street bikes back there a few times. At least one Harley. Doesn't take much more room than a headache rack. Need a rack that will drop down to the ground.

 

You can move trailers back so it doesn't touch the bike.

 

You better ask on that one but if you just dont want to walk to the truck stop they have electric scooters that would fit inside the truck and do 15-20 mph
And yes 5th wheel can move back but you have to be careful with weight dont want to unload the steers to much

 

I can't imagine a company driver being given permission to put a motorcycle on the truck. You would be reducing the freight capacity by 500-800lbs and adding liability for damage to the truck and others should the motorcycle come loose. I've seen small dirt bike style motorcycles mounted to the front of trucks with a couple of brackets added to a moose bar, but these were O/O trucks. 125cc - 250cc for hopping around town.