More open patterns aren't necessarily bad. Wads can vary in cost and performance too. Wads are made from polyethylene plastic. The problem with recycled poly is that it is harder to control the blend of plastics it contains. This can translate into wads that don't seal quite as well in cold weather.
Cold weather makes plastic get harder.
You want the wad skirt to remain flexible enough to seal against the walls of the hull and barrel. If it doesn't, you can get bloopers, or at least off-sounding shots. I have definitely noticed some off sounding shots with Remington Gun Club promo loads when used in cool weather in a gun with lengthened forcing cones. There were no off sounding shots with premium target ammo. Whether the problem was the wad, I can only guess, but I think so.