Where one might see polar bears waiting in readiness? (2,3)
I believe the answer is:
on ice
I believe this clue is a double definition.
'where one might see polar bears' is the first definition.
(polar bears roam on ice)
'waiting in readiness?' is the second definition.
(on ice means ready or prepared)
(Other definitions for on ice that I've seen before include "In abeyance" , "Predatory insect" , "held back?" , "delayed" , "Waiting" .)