It depends upon time of day, the sunspot cycle and most importantly the frequency. For the next several years 160 and 80 meters often support NVIS propagation. Even a low horizontal antenna may work. 80 meters during the day, but not always in the evening, however typically this is for short range QSO's probably less than (or much less than) 200 miles. During the summer months often noise on 80 and 160 is bad. OCCASIONALLY, in good sunspot years 40 meters may support NVIS propagation during the day out to possibly several hundred miles. I have had good QSO's on 40 and 80 with dipoles laying on the bushes and zig zagging all over the place, average height probably less than 5 feet, not ideal, at least 20 or 30 feet better. NVIS not probable above 7 MHz.
A vertical is NOT a good choice for NVIS. So IF you operate near significant ham populations, and want to get over a big hill, then 80 may be your best bet. Sometimes the band holds up and even improves in the late afternoon, and occasionally NVIS still works into the early evening hours (but often not). NVIS is high angle radiation, (near vertical) and sometimes gives good results out well beyond 50 miles, and very occasionally hundreds of miles. Rick KL7CW