Q400 doesn't follow normal rules and is limited to FL250 due oxygen drop down in the back.
Even at MTOW your doing 1000ft/min between Fl240 and FL250 with ISA +10 doing 190 plus knts. Then it will quite happily the accelerate to 230 + knots.
Anything over 30 min sector it wouldn't be unusual to climb to either FL240 or FL250 cruise. At cruise you would burn a rough ton an hour.