I'm fairly certain the Pan Am/SFO slide lifting was caused by an over-enthusiastic helicopter hovering too close and the downwash caused the slide twisting and subsequent injuries.
A slide is emergency equipment. To get off rapidly there are no other options. In most common circumstances, if half the slides are adversely affected by winds, the other half should be operating normally, therefore I think wind speed is not a factor. One might have an embarrasing interview with a flight manager if one declined to operate 'because you didn't think the slides would be usable!'.