Have you considered offering your diners a BYO and perhaps charge corkage or indeed free. I know our fav restaurant do a deal with local off-licence across the road for diners who want to purchase outside the restaurant if none at home etc.
I recently ate in the vintage kitchen which is always packed (we had to book weeks in advance for a thursday night) and they do BYO with no corkage charge (once I think you buy 3 courses).
I suppose you really need to weigh up your costings and charging rates, if you were planning on making most of your money from booze (which is how a lot of restaurants seem to base their business model on) then a licence is obviously necessary.
I would also think that being BYO would help through the early week nights, people might be tempted to go out more if they can bring a special bottle from home.