We used to operate comfortably from Santa Monica Airport, Los Angeles area, I believe, (memory), it was forty nine hundred and something feet, worked well. If you are flying around Europe, you would probably not have a range problem. Stops really well, good brakes, thrust reverse. Depends a bit on takeoff airport elevation, SMO was basically sea level.
Just looked at your thread again, see if they can add 2000 feet, will really reduce the pucker factor. With the extreme swept wing, temperature in the summer time will be a factor. I have an older manual, I will see what I can find in there for you.
Good Luck