Group on the pull up north thus stripped off? Heavens! (7)
I believe the answer is:
huskies
'group on the pull up north' is the definition.
(huskies pull sleds at the North Pole)
'thus stripped off? heavens' is the wordplay.
'stripped off?' means to look at the middle letters (the outer letters are stripped off).
'heavens' becomes 'skies' (I've seen this in another clue).
The middle letters of 'thus' are 'hu'.
'hu'+'skies'='HUSKIES'
(Other definitions for huskies that I've seen before include "Arctic sled dogs" , "Big dogs trained to pull sledges in Arctic" .)