My Dad's first cousin Alan Christopher Griffith emigrated from Pontypridd, Monmouthshire, Wales to New South Wales in 1968. Olivia Mary Page another of my dad's cousins emigrated from Wiltshire, England to Christchurch, New Zealand in 1957. I'm not sure how much difference there is in distance.
If we are talking about direct ancestors that would be my parents, who emigrated with 6 children under the age of 13 from Birmingham, England to Oakville, Ontario in 1966.
Edit: Distances are from Pontypridd, Monmouthshire, Wales to New South Wales 10,661 miles and from Devises, Wiltshire, England to Christchurch, New Zealand 11,834 miles, so the Page family travelled further.