Look, the rationale of pre-authorized business class travel for gov't executives (PS EX1s and above which includes CF Capts(N)/Cols and above was that executives were a) busy and b) fiscally responsible. Those execs, the reasoning went, would want to keep their time out of the office to a minimum so that would travel at thew last minute and they would need some rest on long haul flights if they were to be ready and able to represent the Gov't of Canada at important meetings.
I knew one exec who almost never went business class. He was in the midst of a divorce and he had a girlfriend in whatever city. He always tried to travel as far ahead of his meetings in that (foreign) city so he could to spend time with her. He was a good guy so he always travelled economy and claimed his weekend hotels - fair enough, I thought and still think.
I routinely declined business class on many domestic trips (including Washington) because my directorate travel budget was always overcommitted, but I and my deputy (Eng-6) and Chief Engineer (LCol) used business class for most flights that were long haul including even Brussels and Genevan for the reasons it was intended and available for us.
I travelled on business quite a bit in my last job in uniform. This was due to taking long, long haul flights and having to work on arrival. Sleeping in pod crossing the Pacific or going to the middle east allowed that.
If there wasn't funding for business the boss made sure there was funding for a rest day on arrival.
Travel to Europe or across Canada, nope, unless you had upgrade credits and did it on your own. Luckily Ottawa had a flight to Heathrow that left in the evening and arrived in the moring local time. Book a bulkhead, cattle class seat and sleep the trip away like a good soldier.