I've kept my eye open for a Hopper link, but so far, I've yet to find any interactions between the Hopper family and the Blagraves whatsoever. I know that there was a John Blagrave who was a contemporary of Henry Blagrave I and lived in Stafford Co., VA in the mid to late 1600s; I know nothing further about him, whether or not he left a widow or children, etc. There were also a few other early Blagraves mentioned in VA -- Richard Blagrave who arrived before 1691; Francis Blagrave who arrived before 1663; George Blagrave who arrived before 1654; and William Blagrave who arrived before 1662 and lived in the vicinity of York Co., VA. I've found no additional info on any of these early Blagraves, so I don't know if they returned to England, died without issue in Virginia, moved to another colony, or left descendants.
So, unfortunately I don't have any answers for you regarding the connection to Blagrove Hopper, but I'm still looking!