Simon, privet will do just fine in the Zone 5 portion of Michigan. I live in West Bloomfield, and in 40 some years of watching it, I've seen it winterkill to the snowline ONE time, the extremely cold winter of 1994, when the windchills went to -80 and the actual air temp to -35 to -40. It rebounded so quickly, though, that by midsummer, you would never have known anything happened. In fact, I personally feel it's a good idea every five or six years to wack a privet hedge to the ground. This rejuvenates it and gets rid of all of the dead wood, etc.

Other possibilities would include chinese elm, tallhedge/rhamnus, several kinds of willows (Salix 'Rubykins' or Salix alba 'Britzensis', redtwig or yellowtwig dogwood.

I don't suppose you know anyone with a big privet that would be willing to give you some branches, do you. Privet grows quite easily from twigs stuck into moist soil at this time of year, especially if you use some rooting hormone and make sure to keep them moist. I've started privets this way several times with good results. THAT would be a really cheap way to start a hedge.

privet would make a beautiful hedge for the length of your driveway....but it has one drawback---it needs clipping on a regular basis.
I had one in my city home--we live in the country now--and hubby didn't mind at all getting out and seeing to the clipping. We had one big advantage, a neighbor who sometimes assisted on his side--but we preferred doing it ourselves.
Another hedge you might consider is "barberry".
No longer the bad boy--it is now one without thorns and does not endanger grain crops like it once did since it could transfer rust to such crops.
It is still the pretty one with its red foliage.

There are varieties that still have the thorns so if you have pesky kids who like to jump through a hedge, maybe this one will interest you.

denninmi, how many rows do you plant to obtain a hedge?

Privet can be weedy in some areas, although it does make a nice hedge. Have you thought about the usefulness of arborvitae as a hedge candidate? Takes to pruning well, isn't weedy, evergreen, and the birds like it for winter protection and nesting in (something I know I enjoy!).

Here is a link that might be useful: Arborvitae

Any updates on this?