As Ratbag says, set the treadmill incline for 1-2% and start running. Does the treadmill you intend to use have a 'random' course generator or a 'hill' session? It's worth using these one a week at least for the speed work, then you can enjoy your long run at the weekend in the daylight. Is it worth putting up an advert in your local gym or asking friends for a running partner, or joining the local running club?