Then do some WOM. Invite some important people (say gourmet blogger) to try your dinner sets. Have them to promote your restaurant (Of course you have to provide top quality or value). Make people come to you, even if they have to drive a long way to come to your restaurant.
Absolutely agree... If you market your restaurant as being a great dinner experience, they will come in droves.
Do you offer delievery service? if the district is dead, then everyone is someplace else, like home watching TV, calling for delievery...If you are good in the day, but not so much at night, then delivery can help you out if you do not offer it...Because if you do not deliver, then they call someone else at night for food.
If you do a little survey amongst your customers (especially when it is busy) as to what they would like as an incentive (call it a prize), it would give your options to go from there