There is no legal requirement to carry the POH, even when travelling to another country
How do you do your weight & balance calculation without it? How about calculating required runway length? I like to bring it with me. Better make sure you bring it with you if go to Germany (fast cruise or not) as it has to be onboard the aircraft there.
Anyway, sounds as if a flight is something which you just need to get over and done with in a hurry. Don't you enjoy it?