It's certainly possible - Danny Spence (http://nightflyphotography.blogspot.com/2010/07/large-format-astrophotography.html) has done some astrophotography with 15 minute exposures on 4x5 film, and a search for "large format astrophotography" will pick up some other examples.

I remember reading something about LF astrophotography in a book several years ago - I think one issue the author came across with very long exposures (as in several tens of minutes, to hours) was that the film could absorb moisture from the atmosphere and distort, so that it was no longer laying completely flat at the focal plane; I think his solution was to improvise a vacuum back from a double dark slide - he drilled a number of small holes through the central plate, attached a small hose (maybe aquariun tubing or similar) to a hole in the back dark slide, and sealed the back side - thus creating a vacuum chamber where the other sheet of film would usually go. he then attached the hose to the input side of a battery powered air pump, so that the suction through the holes in the central plate kept the film flat against the plate.