alright, had a similar worry last year with BMI.
Two of us went, we chose a tactic of having one big bag with all clothes etc in it which one of us had as 'main luggage' and then the other turned up with the mat (which was a Franklin Drop Zone, so one of the bigger ones).
Got some funny looks, but otherwise they were cool - they x-rayed it, made us take off the straps and then we had to wait for the geezer to bring it on a trolley cos it wouldn't fit into baggage claim ting...