Possibly, but, if only 18" is out of the ground, and 24" in the ground, and all it's really doing is supporting the base of a cattle panel.... I would think it should be fine... I mean, a few cinderblocks set on the ground at the base would probably WORK if not be super secure.Not necessarily where the frostline is probably much deeper than in VA.
You would think that the frost would actually help since when the ground is soft and sloppy is when our posts get loose and want to move around (1,000 pound animals like to scratch their butts on posts), when it's hard as a rock the fence doesn't budge.
But, I have never built a fence in another state, so you could be perfectly correct.