Well Jo. I wouldn't go, but that's just me. I am sober since May of 2008 and if the party is centered around drinking I still won't go. Not because I can't handle it but its boring to me if all its about is people drinking. In the beginning of my sobriety I wouldn't have been able to stay sober. I'm not sure I understand why your son can't go with your husband. Does he ever take the 3 kids any where without you or are you always there with him?
I can tell you my son that is 6 years old would rather have a sober mommy then go to a party. I would even have him tell you himself if I could.
My two cents.