Blair on a trip to a hall that's this grand? (8)
I believe the answer is:
baronial
'hall that's this grand?' is the definition.
'baronial' can be an answer for 'grand?' (I've seen this in another clue). I am unsure of the remainder of the definition.
'blair on a trip' is the wordplay.
'trip' indicates anagramming the letters.
'blair'+'on'+'a'='blairona'
'blairona' anagrammed gives 'BARONIAL'.
'to a' acts as a link.
Can you help me to learn more?
(Other definitions for baronial that I've seen before include "of the nobility" , "Pertaining to a lower noble" , "Pertaining to a peer of the lowest rank" , "Impressive in appearance" .)