Effects of making smoothies in advance
I make smoothies every morning for my wife and myself (and have for over a year now), and when working out also added protein powder.  The only difference between our recipe and yours is an inclusion of a few ounces of greek yogurt.

On the days when I knew the workout would run long (and potentially make me late for work), I was making them the night before with no problem.  As yossarian said, as long as you make sure the protein powder is fully blended/dissolved you'll be fine.  I've noticed no graininess/texture difference between night-before and morning-of.

The ingredients do separate a little overnight, but a quick shake or stir and they're back to normal.

I would say to try it and see how it works with your exact combination of ingredients.  

Something to watch out for: my wife swears that sometimes, making them beforehand would cause a bit of a "sharp" edge to the taste of the smoothie - if this is true, my guess would be the interaction between the acid in the fruit and the base in the dairy.  But, not being a chemist I can't speak to that.  I can, however, say that I personally haven't noticed a difference based on whether it was made the night before or not.

I see that you're not using ice; I don't know if you're using frozen berries or not, but if you're used to a chunkier ice-like smoothie from frozen berries, you'll lose that texture of course.