I understand. One of my favorite headphones are Beyerdynamic T2. They are exceptionally hard to drive. One of my headphone systems is shown under my ID.
For over forty years I have traveled with headphones and stayed up on contemporary technology. Fairly recently I traveled 250,000 miles a year.
First question… is this business travel… or where most of the time you will be in noisy environments? I found that taking high end headphones on planes, in hotels and airports to be too compromised to be worth it. The ambient noise will wash out the high frequency sound and reduce the dynamic range to perform incredibly poorly.
In this case get a set of Bose Quiet Comfort, they will be unbelievably better. The noise cancellation alone while traveling will make your trip sooo much better. I put them on when I get in the airport, noise cancellation only, and take off at my destination. I would listen to music some of the time… no wires. Their sonic presentation is a bit cartoonish… but perfectly balanced, punchy and good sounding for noisy environments.
If you are packing up, say to go to a cabin or something for a couple weeks. Where the actually travel is not important. In this case I would either recommend getting Ultrasond Edition (maybe used). These are smaller and can be driven easily with an iPhone or iPad. Focal are also easier to drive… a portable amp with these would be good. The key here is more made to sound good from a source you already have.
Alternatively, if you are just going and staying in one place. Is your amp at home a small footprint? Wrap it up… take it?
There are lots of alternatives. If I know more about what you are looking to do.