It seems we may have some family ties.
The problem with finding the Boddon family is the name spelling, in various forms it can be Boddon/Boddan/Bodden/Boddin or Bodin, I presume it depended on the form filler.
I found Andrew Bodden (surgeon) 1841 census living in Carsphairn, born c.1806
Wife Margaret (nee McMillan) born 1811 with 3 daughters and 1 son
Elizabeth (daughter aged 10)
Jane (daughter aged 7) my maternal ancestor grandmother x 4
Robina (daughter aged 3)
Robert (Son aged 6 months) presumeably your great great Grandfather.
I have hit a brick wall with Andrew Boddon, however I did find his wife's Margaret's parents who were Robert McMillan (born 1776) and Elizabeth (nee Locke born 1778) living in New Bank (Mill) Kilpatrick Durham.
Robert McMillan was a Farmer (21 acres) and a Manufacturer (possibly dyer/weaving) with 5 daughters and 1 son, employing 3 men.
Elizabeth born 1803
Jean born 1805
Margaret (Boddan) born 1807
Janet born 1813
Marion born 1828
John unknown but may be the youngest.
All name spellings are taken from Robert McMillan's Will/Testament dated 1847 and executed 1853, so I presume are the correct ones but can vary on some documents.
I cannot find any records for the deaths of Andrew or Margaret Boddon but they are mentioned in Robert McMillan's will in 1847 (he mentions that Andrew is "sometimes Surgeon at Rocketford", they seem to have disappeared by 1851. Elizabeth, Robina and Robert (aged 10) are staying with the Grandparents McMillan in the 1851 census, Jane being married, so I presume Andrew and Margaret are dead
Anyway that gives you the tie to the McMillan name and family.
All the best
Tom