Hello,
While searching (in another topic) for a Samuel Meade who migrated from England to Ontario (Canada) in 1870, I found in the Quebec Passenger Lists Index 1865-1900 (from Library and Archives Canada site), the arrival at Quebec (Quebec, Canada), 06 May 1869, on the "Crocodile", the family of Cornelius Mead (42), Elizabeth (48), William (17) and Harriett (14).
They clearly match the family you are looking for.
A quick search on Family Search provided the marriage of a Harriet Mead, 23 (daughter of Cornelius M. & Elizabeth Maidment) with a Daniel Sullivan, on 30 Jan 1879 at Hamilton (Ontario). Indicating that the family was still in Canada by then.
I hope that this will be of some help, after all these years without reply...