I have a general policy against speculating too much about things that I have no way of really knowing. Thus, I make no belief statement regarding God's creative endeavors (age of the cosmos, theistic evolution vs. creationism, etc.) other than knowing that He is indeed the Creator and Sustainer of all things. Likewise, I make no belief statements regarding specifics of how this current existence will transition into the next other than being pretty confident that the dispensationalists are way off track.
With that in mind, I really have no idea what happened while Jesus was in the grave, other than believing that He was truly dead. However, I do really like the idea that He was in some Hades-like afterlife sharing the Gospel with those who had passed without having the opportunity to hear it prior to death. And I would hope that this would not be limited to just those who died in the days of Noah or anytime B.C. but also to those who had no access to the Gospel even after the Christ-event (Incas, Aztecs, Mayans, etc.). This really lines up with what I believe about the character of God as revealed in Christ. I believe that all people will have the opportunity to accept or reject Him, and if He ministered in Hades during His three days in the grave, then that is a perfect explanation of how those people had the opportunity to respond to Him.
So I do think that Jesus descending to and leading forth the prisoners from Hades matches up well with what I believe about His character. But as there is really no way for any of us to know this, I am not going to get too stuck on the idea.
Regardless, it is best for us to be sharing the Gospel with the lost here and now, not to give them a ticket into heaven when they die, but rather so that they can enter into eternity through relationship with Christ now, be set free from brokenness, and begin participating in God's restorative work.