I tried doing this but the second I take my eyes off the screen to check the timer I'll get 1 pixel too close to the deer, and using a timer outside the game as the only way to survive a specific enemy isn't interesting gameplay anyways. It's just not viable to wait outside the cabin for 15-20 minutes at a time (the clowns specifically counter this anyways, even if you run right towards them the second the music starts you might not reach them in time).