Apparently there was a Sunday School, dedicated to All Saints in 1899. The web author has found no mention of a church with that name in the parish, with the exception that the church listed above has a full name of "All Saints and the Blessed Virgin Mary.".
Winthorpe is both a village and a parish that lie on the North Sea just north of the east end of the A52 trunk road, about 13 miles northeast of Boston and 12 miles east of Spilsby. The parish includes the hamlet of Seathorne, home of the popular Lookout Pub on the beach. Skegness parish lies to the south and Burgh le Marsh parish to the west. The parish covers almost 2,400 acres. In the 1870s, most of the parish was grassland.
The name Winthorpe is from the Old English Wina+thorp, or "hamlet of Wina". Not mentioned in the 1086 Domesday Book, the village is given as Winetorp in the 12th century. [A. D. Mills, "A Dictionary of English Place-Names," Oxford University Press, 1991]