There seems to be little to none of source data, other than his marriage mentioned in the Sarah Preston of Virginia. Very clearly, a different Sarah. I found some unsourced data which may provide some clues for further investigation. The marriage record (Andover, V-2, p. 308) as it appears on the subscripton americanancestors.org site, recites "John Stacy, of Hampton, and Sarah Preston, Jan. 23. 1723-4* [*= intention published]." A geni.com genealogy has interpreted this to mean Hampton, Windham County, Connecticut Colony (John Stacy, born 12 Dec 1674, died 1746). However, since Sarah Preston of Mass. is said to have been born in Andover Mass. in 1705. this would have her marrying, at age 19, a man of 51 years of age. Not impossible, but implausible. I would posit a John Stacy, son of John, a more likely choice. I found no record for a John Stacy born anywhere in Connecticut circa 1674 (nor a possible son of John born 1695-1705).
The possibility of the Windham County connection is somewhat enhanced by the Barbour Collection for Killingly (Killingly VR, p. 154, also at americanancestors.org) which reports 3 sons born to John and Sarah Stacy between 1729 and 1733. Of course, there is no record source that connects the couple married in Massachusetts Bay with the couple in Killingly.
Solely a possibility at this point, far from a probability.