Were Abraham and Sarah "Separated"?

Melissa, Keegan and I are in Kimberling City right now staying with her parents down at their lake house. We made the journey so we could be here for David's viewing and funeral. By the way, over breakfast this morning, we were all discussing people we have known who have died and at the viewing were laying on chaise lounge chairs because the family hadn't yet picked out a casket! To me, that sounds like the foundation of a good country-western song! "Prop me up beside the jukebox when I die...Lord I want to go to Heaven, I just don't wanna go tonight..."

Anyhow, usually when we come we worship with her parents at the Kimberling City COC, even though the average age is...well let's just say "blue-hair." Last night, the teacher was giving an account of Abraham's life and was bringing up some rather interesting questions, which got me thinking. The teacher never said this, but based off of one of the questions he asked, I am asking the question: Could Abraham and Sarah have actually been "seperated" after he took Isaac up to Mt. Moriah?

The text says that after the blessing from God, he went with his servants to Beersheba where he began to live. But at the beginning of the next chapter, we find out that Sarah has died and she was living at Hebron in Canaan.

What was the reason for the dual-household living? Was this sort of arrangement common in those days? Was Abraham starting a new family with Keturah by this point? The text doesn't mention them until after Abraham sent for a wife for Isaac, but that does not mean that their family had not already been started. Was there friction between Sarah and Abraham over "the sacrifice?" Did she tell him before he left with Isaac, If you even think about doing it, don't you dare show your face back here! ?

We know that Abraham still must have had great feelings for Sarah, as he journeyed back to Canaan to "mourn for Sarah and to weep over her." He also bought some prime real estate to bury her in, and which he was later buried in as well.

What to think of this? Who knows? I suppose it is one of those things that the Word is ambiguous about. Have any of you studied this at all? Do the Jewish traditions or extra-biblical texts have anything to say about this subject? I would be interested in your comments or information.