But honestly, who here would espouse that the best thing to do when you lose the engine in a SEL is to try to calculate what glide speed you should use to reach a safe destination?
To be safe, would you not just set the best glide speed by using full back trim, as every SEL that I know will have the best glide speed by using full back trim?
And wouldn't you focus on the emergency rather than the glide speed?
And, absolutely, without question, the best glide speed, does not change with wind. The best glide distance might not be achieved by the best glide speed, but the Vspeed does not change due to wind.