Early February is nice. We made several day trips then.
The average temps are low 70s for the high and low 50s for the evenings. Crowds are low. Weather is generally nice (warm in the sun, cool in the shade) but its too cool for me to swim in the heated (supposedly!) Fort pools.
Rates go up dramatically around Valentines Day but if your schedule allows you to go in early Feb I would definitely recommend it.
Bama ED
PS - I think early Feb is still Value pricing for campsites. Those are among the lowest regular rack prices you'll get at the Fort....