Combining Separate Rooms to Create a Minyan

I was recently at a minyan in a beis ha'avel, and the minyan comprised six men in the living room and five in the dining room.  The two rooms were separated by a hallway and walls, with large doorways.  A person standing in one room could easily see the people in the other room.  Do we have a minyan?  I checked to see what the Internet says; and I was once again amazed at how times have changed!  It used to be that to be simply wrong was easy, but it required some work to be thoroughly convinced of the truth of your error.  Now, each and every one of us can do the same with a few keystrokes.  In short, almost everything I found was not only wrong, it was convincing, because they often began with irrelevant and misapplied truths.  So I felt I needed to post this.  Of course, remember what I say in my profile.

So, do we have a minyan?

Yes, we do, sort of, bedieved. Mishna Berura 55 sk 57 ("where it is difficult to avoid, perhaps we can be lenient.")

No, we don't, absolutely not.  Aruch Hashulchan 55:20, 23.  He says this you also don't have a minyan when some are in the shul and some in the Ezras Nashim.  And the Gaon and the Chayei Adam, who hold that making a minyan is not comparable to making a mezuman for bentching, so the "seeing each other" rule is not applicable.
The Aruch HaShulchan sk 20:

מיהו זה וודאי העומדים בעזרת נשים לא יצטרפו עם העומדים בבית הכנסת, אף שיש חלונות מעזרת נשים להבית הכנסת, ורואים אלו פניהם של אלו, כיון שמחיצות גמורות הן – הוויין שתי רשויות.

And even the Mishna Berura has strong reservations. 

I should point out, though, that קלקולו זהו תיקונו - if the mechitza allows you to see over it and you and the men behind the mechitza see each other, then the Mishna Berura is noteh to be meikil.

This is often seen as a surprising halacha, because many of us are familiar with the Gemara in Eiruvin 92 that allows creating a minyan by combining groups that are in two courtyards that open to each other under certain circumstances.  The problem is that most poskim say that the Gemara only applies when they are in courtyards, or one group is in a courtyard and the other in a house, but if the two groups are in separate rooms or houses, this amplifies their separate identities, and they do not combine at all.  On the other hand, the Rashba in a teshuva (96) says that it is possible that when the members of the two groups can see each other, they automatically combine.  The Rashba, though, only says that this is possibly true.  (See Biur Halacha 55:13 dh "ve'lachutz" and MB sk 57 with Sha'ar Hatziyun 60.)  So the practical rabbinics divides as to halacha le'maaseh, according to the Aruch Hashulchan and the Mishna Berura respectively, and at best you have a bedieved.

Please note that this discussion does not apply where there is a complete minyan in one room, and others want to say kedusha with them.  Where there is a good minyan, it is easy to become a part of them.  Our discussion only involves a case where you are trying to create a minyan by combining separate groups.