I'm 53 and I have several friends in their early mid 20s, we get along great. and no they don't want to sit around and drink or what not. they are nice responsible young people with spouses and children and dogs.
the issue is your husband inviting people left and right without calling and asking if you are ok with it. and you aren't, so you need to make that clear. and if he says what's the big deal then you need to spell it out to him what it is. thanksgiving food is expensive, it's time consuming and you were not prepared to entertain.
since the invitations have been given and accepted, now you can decide what you want to do. If it were me? I'd have it catered, honey baked ham compay and boston market restaurant cater, some grocery stores do also...you might have to pick it up but it's all in disposables, heck send leftovers home with everyone if you don't want it in the house.
Or go somewhere like golden corral, that's what I did when my ex invited all of his brothers/spouses/children to the house for christmas with out asking...no way was I cooking for 14 people in the state of anxiety I was in just in dealing with his very ill mother for the 2 months prior.
do what ever is the easiest for you, if it costs your husband some money, perhaps he will think twice the next time.

(or worst come to worst, you can make it potluck, call everyone on the list and tell them what you want them to bring)