I'm thinking it would have to be well over the limit to be noticed.... How many folks can look at a bag and have any confidence in saying it is 65" rather than 62?
My only experience was with a large boxed item.. I had actually reduced the size by cutting about 8" off one end (box was roomier than necessary for the contents) and taping the end piece back on... it meaured 68" overall... As it was only about 8" "thick" most of the size was in length and height....
A box that size is a little awkward to carry so I made a loop of rope.. placed it around the box and taped it down with the ends forming a set of handles..
When I checked in the ONLY comment from the agent was "Oh.. you put
handles on it!" and he whisked it away...
Make it easy on them being the key????