High speed flight? Why are you worrying about gear and flaps during "high speed flight". Maybe that's the trick part of the question.
My observation is hydraulic pressure is normal as long as N2 is 5-8%. Below that control movement reduces hydraulic pressure. Pressure returns to 3000 PSI as soon as flight control input is stopped.
Three deadstick, no APU, flameout landings in a 737 sim. Flaps and gear operated normally. Maybe slow(too busy to time them) but they worked.
Real world might be different. Good luck. Report back if it ever happens to you.
