It depends on the distance requirements for each. If I'm required to stay in my home for the staycation, then vacation. If I'm allowed to travel and stay anywhere within say a 100 mile radius for a staycation, then staycation. I'm not staying in this box of sadness for an extended period of time, but if I can camp down the way, then longer is better.
Would you rather camp outside for one month or say with your in-laws for one month?