About 35 rolls of 120. (7 boxes).
Since i can go through several rolls an hour, that is not a remarkable amount. I think I brought four boxes for a 30 hour trip, once. 120 is the only format where I shoot like that, 4x5 and larger are much slower, and 35mm takes me weeks to finish a roll.
I regularly fly with about 40-60 rolls, it's more dependant on the weight/baggage restrictions, some airlines only allow one carry on bag others one bag & a laptop case so that's really a determining factor.
Occasionally I fly with film, a dev tank & chemistry etc and process while abroad.
Film's considerably more expensive in Europe, you could always post some ahead and maybe make contact with an APUG member with a darkroom and process while in Europe (B&W), there's labs for Colour C41/E6 in most cities.