Well, that was a bust, as far as the 1630 sailing date.

In the Great Migration Begins: Immigrants to New England, 1620-33, it says that "Banks includes Thomas Cakebread and his wife Sarah in the Winthrop Fleet of 1630, and claims they were from Hatfield Broadoak, Essex, but there is no support for either of these statements [Planters 68]."

There is some good info in the entry about Thomas Cakebread, but it also raises some questions between what Morse says about his wives and what is listed in this book. This is not the entire segement, but I've extracted the parts relevant to Capt John:

ESTATE: Granted fifty acres in Great Dividend in Watertown, 25 July 1636 [WaBOP 5]; granted eight acres in Beaverbrook Plowlands, 28 February 1636/7 [WaBOP 7]; granted eight acres in Remote Meadows, 26 June 1637 [WaBOP 9].
In Watertown inventory of grants, had received eight parcels: four- acre homestall [crossed out]; six acres of upland; five acres of meadow; nine acres upland beyond the further plain; twelve acres upland beyond the further plain; fifty acres upland in the Great Dividend; eight acres in the Remote Meadows; and eight acres plowland in the further plain (Beaverbrook Plowlands) [WaBOP 96]. (In the inventory of possessions and the composite inventory, most of these parcels were held by John Grout, who married Cakebread's daughter [WaBOP 42, 127]. On this basis Grout on 3 March 1670/1 laid claim to the grant of a farm in Watertown, but was rejected: "Ensign Grant [a misreading in the transcription for Grout] demanding a farm in the behalf of Ensign Thomas Cakebread we returned him this answer that we had with seriousness considered of his demand and had also sought the town book and by all that we could find in the town book we do not find any ground from the town book to answer his demand and therefore left him to his liberty" [WaTR 1:106].)
In an undated but early Sudbury record is a list of "such lands as were given to gratulate some persons for some service done by them which meadows are ratable," a list which was annotated to include later grants:
Given to Thomas Cakbrad for and in consideration of building a mill forty acres of upland or thereabout near adjoining to the mill and a little piece of meadow downwards and a piece of meadow upwards which may be sixteen or twenty acres.
Also there is given for his accommodations for his estate thirty acres of meadow and forty acres of upland.
The 9th month the 14th day
All this land formerly given to Ancyente [Ensign] Cakbread is confirmed to him by the freemen of the town in the [not completed].
The Cranbery Swampe formerly granted to Antient Cakebred is further confirmed to John Grout the 8th day of May 1643.
Also granted to Sergt. John Grout the swamp lying by the now dwelling house of Phile: Whale to pen water [for] the use of the mill & the [rest] of it to remain for the use of the town" [SuTR 26].
On 18 November 1640 Cakebread was granted forty-four acres in the Great Field as part of the third additions of upland [SuTR 30].
On 1 May 1645 there was "granted to Sara Cakbrad widow forty acres of upland lying in the south part of the town bounds joining to the east side of the lands of Thomas Goodenow" [SuTR 53].
On 26 May 1646 "it is also ordered that Edmond Goodenow & Hugh Griffyn shall lay out to the widow Cakbrad so much land as is taken out of the lands which Mr. Pendleton & Edmond Goodenow laid out about the mill for Ensign Cakbrad which lands were taken out for enlargement of the highways or lyeth within the fence of Thomas Browne's second division of upland" [SuTR 81].
The Sudbury land inventory contains a list of the lands possessed by the widow Cakebread [SuBOP 131].
BIRTH: By about 1595 based on estimated date of marriage.
DEATH: Sudbury 4 January 1642/3.
MARRIAGE: By about 1620 Sarah _____ (assuming she was mother of his child); she married (2) Sudbury 7 November 1649 as his second wife Philemon Whale; she died at Sudbury 28 December 1656 [TG 6:131].
CHILD:
i MARY, b. say 1620; m. by about 1640 as his first wife John Grout of Watertown and Sudbury [Dawes-Gates 1:663].


COMMENTS:
The evidence for the daughter Mary who married John Grout is given by Mary Walton Ferris, who cites a petition in which John Grout refers to Thomas Cakebread as his father-in-law [Dawes-Gates 1:663-64, reproducing the original petition]. (Savage had these marriages completely wrong, as did many other writers.)
As Ferris also notes, "If the early claim that Mary, first wife of Ens. John Grout and Anne first wife of James Cutler were sisters, can be proved, it means that Anne was another daughter of Thomas and Sarah (_____) Cakebread" [Dawes-Gates 1:663]. This claim appears only in the secondary literature, and seems unlikely, since the entire estate of Thomas Cakebread seems to have ended up in the hands of John Grout.