Yes any speed.
When you say elevator runaway on the CRJ it is actually a stabilizer trim runaway as that is what is trimmed for flight.
The CRJ has a movable horizontal tail in which the entire horizontal stab is trimmed as needed for flight. The Elevators attached to the rear of the stab can overcome a runaway trim situation. The elevators and rudder are powered by all 3 hydraulic systems (1,2,3). Three PCU actuators (1,2,3) are on each the rudder and elevator. In the event of one bad PCU actuator the other two will overpower the bad one.