You could try to ease into the new time by waking 5 mins earlier/later per previous morning, two weeks before the switch.
It's like the shaggy dog story about a business consultant who was hired to improve efficiency at a port. "The first thing you need to do," he concluded, "is reschedule your tides."
If it makes sense to adjust our schedule according to the season, let's just do that, instead of shifting our clocks and pretending nothing's happened.
Then why not agree to change the office timings at once?