First, understand that deformed wings are not always caused by mites although it's a good indicator of varroa. Second, make sure they are actually deformed wings and not chewed wings which might indicate fighting from robbing (common this time of year). Third, I only use oxalic acid vapor if I treat which can be used at almost any temperature and is a quick fix. Fourth, 10 or so bees is usually not as strong indicator of a serious problem...keep your eye on them for any worsening.
Scott