I have been doing a lot of testing recently. My focus has been on long-range autonomous flights and how the craft behaves in winds. As the props get larger on a quad, the stability in wind actually decreases. There are two reasons for this:
The props have a larger swept area, and therefore have more area exposed to the wind, and
The props are going slower. Bigger props don't spin as fast as small ones. Consider a car that is sitting on a highway and not moving. The wind is rapidly changing direction and is gusting from 10-20MPH. The car 'feels' every change in the wind. Now, move the car down the road at 60MPH. The car is still affected by the wind, but since the car is moving and is creating its own 'wind', the actual wind is a small percentage of all the forces on the car. So a little 6" quad is quite happy flying in a 25MPH wind, while a quad with 16" props has a much harder time.
Another thing to consider is maximum speed. A small quad 'screws' through the air faster than a big one. This has to do with prop pitch and RPM (more about that later). If a craft can fly at a maximum speed of 30MPH, it obviously cannot fly properly in a 35MPH wind! Small quads often do have a maximum speed of over 40MPH, while a big quad with 16" props may have a maximum of 20-22MPH. It would struggle to hold its position in a 15MPH wind.
Anything flying over the mountains (towards Santa Cruz) is likely to encounter some decent wind. Any craft that makes the trip will have to take that into account.