2001 Lincoln Continental weak brakes when cold

I recently had the front brakes on my wife's 2001 Lincoln Continental replaced at the local Lincoln dealer. When the car has sat overnight or for several hours,the car does not stop right away for approximately 1 mile.Before we had them replaced,we never experienced this problem before.Once the brakes heat up,they stop fine.Any ideas? My wife is understandably nervous about driving her car in the winter,as we live in a resort town in the mountains and get quite a bit of snow.I would appreciate any suggestions.I currently am getting a second opinion at another service department.As of this moment ,they have not checked it out yet.Thanks for your help!!