Attempting to answer Centaurs’s opening question logically;
Emergency manoeuvres - EGPWS Pull Up, Windshear - recommend speeds as low as ‘respecting the stall warning speed’, normally 1.1 stall speed.
However, this assumes that the aircraft has a stall warning system which corresponds with the general certification requirements - surprising if not. Furthermore, that the high level stalling characteristics are similarly warned, and that the stall margin (Mach effects) enable reasonably safe flight at this low speed - possibly not.
Given that altitude loss is not an issue at high altitude - no not even considering risk of collision etc, etc; focus on the primary safety issue. Then starting a gentle pull up after loss of stick shake, aiming to level / climb at a higher speed (min manoeuvring?) would appear to be safe. But further problems are the sensitivity of the speed display at altitude (flap speeds, etc, not available) and the use of Mach for reference. These similarly can be overcome by trading altitude for speed - turb speed, which might be required anyway for turbulence/ manoeuvre, i.e. addressing factors which could have contributed to the stall situation
Always test assumptions and logic - comments?