I am too far away to get to Durham Records Office which is likely to be where the registers were deposited, sorry.
I tried Durham Records Online
Their listing says they have baptisms for St Mary the Virgin, Middleton in Teesdale with a date range of 1578 - 1901, with a note that:
There are no baptisms in the register for Oct 1587 to April 1617, June 1621 to Dec 1626, Jan 1630 to March 1633, and 1646-1652. No marriages 1635-1653, 1668-1670. Marriage witnesses not transcribed before 1813.
I searched for Redfearn (plus variants) baptisms, Teesdale District 1745 +/- 5 years and there are no results.
I then tried Redfe*, baptisms, Teesdale District and didn't specify a time frame, there were lots of results but the earliest was a John Redfearn who was baptised in 1769, the family lived at Langdon Beck.
I can see your George in the list, plus a Lydia (1770) and a Joshua (1775) abode for all three was Lodge.
A free search will give you the name of who was baptised, the year they were baptised and the abode at the time of baptism. May be worth doing that and looking down the list to see if there are any 'likely' ones you are looking for - some may have been baptised a lot later than around their birth time - its a straw to clutch at anyway :-) Its a pay site but you can buy credits if you only want a few records and don't need a subscription.
Boo