I believe aircraft with winglets are approved for 2 or 3kts less crosswind limit due to the extra surface area perpendicular to the wind.
That seems rather unlikely, seeing as the surface area of even the largest winglet is really minuscule compared to the (lateral) surface area of the fuselage. Even if they did make a difference then that would only affect gust limits, as a steady crosswind will have the same effect on any aircraft, regardless of shape or even size.