Has it been your experience that the 62 in restriction is not enforced by airlines ?
I have read where folks manage to take a bob without paying oversize charges. I have always found the airlines to be pretty quick to charge for anything oversize or overweight, but maybe the odd shape of the bob slips through?
On a more general note...
I try to fly southwest because they tend to be more bike friendly. No baggage charges for two regular sized checked bags and $50 for a bike in an oversize box (it counts as one of you checked bags). Frontier is supposed to be bike friendly as well.
Personally, the S&S couplers don't solve the problem for me. Since I tend to fly to one place and home from another getting the case moved would become problematic. One answer might be to use a 62" cardboard box, but you would still have to manage to get exactly the right size box to the end point. A soft case would be easier to mail ahead that a hard one, but still a hassle.
I typically just fly southwest with my packed bike ($50) to get to my trip start. I take my gear (in panniers rather than a trailer) in either a $7 thrift store suitcase (which is then discarded at the airport) or in a cheap duffel bag that is either mailed home or carried on the trip. The packed panniers fit nicely in the duffel, but I have to pack more carefully with the suitcase.
To get home I drop the bike at a bike shop and ask them to pack it and ship it home. That usually runs about $50 for the packing and $50 for the shipping. The gear either goes into another thrift store suitcase or a duffel. If a duffel, I either pick one up at walmart, use one that I carried along, or have one mailed to me from home.