To keep your stealth, you need to move at 1/2 speed. So you are correct FitzTheRuke you could move, dash, then cunning action hide, but after that you would be traveling at 1/2 speed to keep your stealth up.
I think you'll need to clarify if your character moves then hides or tries to approach stealthily. In pbp communication is key.
BTW: Darian is stlll in melee range from where he is. 30' move, 30' dash (bonus action), and attack.