May I asked where the information for this marriage came from?
I have checked in Nev Ramsden's Copeland Index (he has indexed all the early parish registers in that part of Cumberland) and he has not got any such marriage in his index. Neither can I find it on FamilySearch.
Ah, I see Ancestry has the Marriage Licence Bond from the Archdeaconry of Richmond. The date on it is a bit dodgy - it says 19 Jan 17 2/3 - so they left out the 3 for the decade. The previous and next bond in the series are from the early 1730s so I think you are right, the date is 19 Jan 1732/3. The year started on 25th March at that time, so in the 1730s this would have been January 1732, but by our reckoning today we would say 1733 - hence writing it as 1732/3.
Now, this date is not the date of the marriage but usually a few days before the marriage took place. The presence of a marriage licence bond is also not a guarantee that the marriage actually took place - they could have still changed their minds!
However, Nev has the baptism of three children of William BLAKE (mother's name not given, as is usual at this time) in Muncaster:
William 08 Jan 1732 (not sure whether this is 1731/2 or 1732/3) - in either case this would have been before the marriage!
Isabel 10 Aug 1735
Elizabeth 14 Oct 1739
If you contact Whitehaven Record Office, ask for the full wording of those baptism entries as well as they might give further clues (if you are very lucky!).