In one breath you say you will take a lot and won't take less. In another breath, you complain about the extra weight of the "hardware" that is used to attach the panniers to the bike. The combined weight of two Ortlieb Sport Packer Plus panniers and two Bike Packer Plus panniers is roughly 8.5 lbs. according to Wayne at the Touring Store. How much of that do you think is attributable to the mounting system? More importantly, how much weight, on a percentage basis, does this hardware add to your total load? For example, I am 210 lbs. Let's say I am riding a Surly LHT that weighs a conservative 30 lbs. I am carrying 55 lbs. of gear in four panniers that weigh 8.5 lbs. Assumning the mounting hardware is 25% of the total pannier weight, that's only a hair over 2 lbs. That's a mere 0.7% of the 273 lbs noted above. If the hardware you are really referring to are the racks, 4 lbs. worth of racks is still only 1.5% of the total load.

As for size, I don't know which Ortliebs you are using, but I recently bought a set of Bike and Sport Packer Pluses. They are cavernous. I cannot imagine anyone thinking this setup is too small and also complaining about a few punds of hardware weight unless they are trying to transport as many feathers as possible.

Don't think a Big Dummy is ging to help you in the weight department.

As noted, get a duffel bag. Put everything in there. And you can always carry one pannier on a flight with you if not everything fits in the bag.