you are quite vulnerable in a light aircraft - a 1kg drone is likely to come through the windshield at normal GA cruising speeds.
in a twin yes, in a SEP even a small 300gr one will probably cause enough damage to the propeller to put it out of balance and possibly cause disintegration ..
That could be on the ground as well. During an airshow I was participating last Summer a spectator behind the barriers was operating a small drone above the taxing line to take photos.it hovered besides and above my turning prop say 5 m away.. I reported it but not sure if they did something .. Not sure the guy doing it had any idea that these can be suck in the props , not to mention jet,s .it they come too close..
We are unfortunately going to see more of those...