I just wanted to say me and a friend thought about this a week or two ago.
300ft (move, dash, dash) every 6 seconds for up to 2 hours.
Monk 10 (shadow / elemental your choice) +20ft speed
Barb 5 (your choice probably bear totem) +10ft speed
Rogue 3 (assassin) +bonus action dash
Druid 2 (Moon)...
