I've had a quick look through the High Roding parish registers (see below) and could only find one marriage, the one in 1769 already mentioned by emeltom. There were banns read about 1800/1801 for a Thomas Crush & Mary Hartgrove but no marriage was recorded. There was a marriage for Thomas Crush in 1802 which may, or may not, be the same Thomas.
I couldn't find a baptism for James about 1796, despite the census references to the birth date and place of High Roding. So there's no obvious connection to James baptised in 1769 to James and Mary.
On the 1841 census there's a William and Ann Hartgroves, living in High Roding, and they appear to have died in High Roding. If this William is the same William that was baptised in 1782 to James & Mary and subsequently married in Willinggale Doe in 1807 to Ann Wheale, it may be worth looking into this to see if the family moved to Willinggale Doe.
NB: It's quite possible that I've accidentally missed from parish records for the family, so I'd suggest double checking these yourself.
Marriages (High Roding):
14 Oct 1769
James Hartgrove (x) of Athrop Roding
Mary Hasler (x) otp
wit: Joseph Dean, Henry Lake; banns (published in each [?] parish)
Thomas Crush [?]
Mary Hartgrove
banns [published between 28 Apr 1800 and 27 Oct 1801; no marriage]
29 Jun 1802
Thomas Crush (x) bach otp
Ann Cliff [?] (x) spin otp
wit: Ann Eastham [?], William Crush (x)
banns: 13, 20, 27 Jun
[Is this the same Thomas Crush as above, marrying someone else? If so what happened to Mary?]
Marriages (Broxted):
14 Jun 1816
James Hartgrove (x) bach otp
Rebecca Baker (x) spin otp
wit: James Baker, Mary Baker (x); banns
Baptisms (Broxted):
31 Jul 1796 Ribbea [?] Baker parents: Thomas & Sarah
17 Nov 1816 Thomas Hartgrove parents: James & Rebecca of Broxted, labourer
Baptisms (High Roding):
31 Dec 1769 James Hargrove parents: James & Mary
19 Sep 1773 John Hargrove parents: James & Mary
23 Apr 1775 Thomas Hardgrove parents: James & Mary
02 Jun 1782 William Hargrov parents: James & Mary
18 Apr 1819 Thomas Baker [?] Hardgrove parents: James & Rebecca of High Roding, labourer
09 Dec 1821 Mary Hardgrove parents: James & Rebecca of High Roding, labourer
06 Jun 1824 Judith Hardgrove parents: James & Rebeckah of High Roding, labourer
20 Dec 1826 Keziah [?] Hardgrove parents: James & Rebecca of High Roding, labourer
08 Aug 1830 Martha Hardgroove parents: James & Rebecca of High Roding, labourer
05 Jan 1834 Richard Hardgrove parents: James & Rebecca of High Roding, labourer
30 Jul 1837 John Hartgrove parents: James & Rebecca of High Roding, labourer
Burials (High Roding):
04 May 1806 Mary Hardgrove
13 Sep 1818 Thomas Hardgrove of High Roding age: 1
16 Feb 1839 William Hartgrove of High Roding age: 25 years
06 Dec 1844 Ann Hardgrove of High Roding age: 60
04 Jul 1860 William Hartgrove of High Roding age: 79 years
21 Jun 1876 Rebecca Hartgroves of High Roding age: 80
16 Apr 1879 James Hartgroves of High Roding age: 83