Airbus350s,
Dear sir, Q400s do 8-10 flights per day and other than the first flight in the morning, the oil temps in the left engine are nice and warm all day long. The PW150 is massively derated for sea level so it's a quite unstressed engine as these things go...Starting it late in the taxi is simply not an issue. It's only because there's a big prop attached that you notice anyway....
Good job by the crew who only get to practice this twice a year mostly...