grey nomad
n. A retired person who travels extensively, particular in a recreational vehicle.
Examples
2000
Mr Jeffcock turned 70 last birthday. He is one of a generation of "grey nomads," old in body but young at heart, backpacking its way around the world. Spurred on by greater life expectancy and better health in old age, they are travelling independently and sleeping in youth hostels.
—Mark Rowe, “Itchy Feet,” The Independent, February 27, 2000
1997 (earliest)
Bev Gosbell knitted her way around Australia - six jumpers in eight months over 25,000 kilometres - while her husband Bob drove the Fairmont and manoeuvred the caravan.

Bev, 63, and Bob, 66, are what are being called "grey nomads" - retirees who pack up to travel, sometimes for years on end, sometimes selling their homes. Outback roads are full of them.

The blue-rinse adventurers move around with an economic freedom the envy of any 20-year-old. According to the Caravan Industry Association, there are up to 15,000 caravans doing a round-Australia trek at any one time - 70 per cent of them with early retirees.
—Anne Crawford, “Carry On Wandering,” Sunday Age (Melbourne), February 23, 1997