Not good to abruptly stop bf as you will get engorgement and other problems like blocked ducts. you can slowly wean baby off but you will miss Breastfeeding baby again and you won't b able to get back the supply. Actually, you can express on your seat under a Breastfeeding cover right? After that, keep the milk and then wipe the pumps. Or you can keep the milk first then throw them away when you go to washroom.
If your work day is 12 hours, maybe you pump once at lunch and once when you reach hotel?
My friend reduced her pumping when she is busy with her parent's wake and funeral for one week. Milk supply is still ok after that when she went back to total bf.