If the cloudbase is 3000' in the mountains then the tops are in cloud. It would be perfectly safe to fly known routes at say 1500' using the goggles to assist. I am not suggesting that SPIFR would be down in the weeds on NVG. It would mean that a lot more transits could be safely conducted at night. Some nights the weather is good but due to the need to be at some considerable MEA to get across the hills the transfers are done by the military. One question never asked is what would happen on a patient transfer being conducted to military limits and there was an accident? These are transfers not rescues and an engine failure then reject lifting from a helipad is rarely practiced by the military and helipad approaches and departures are pretty much at the captain's discretion. Sorry, way off topic!