It would depend mostly on what direction the Ottoman Empire takes.
Ultimately, the fact is that many GPs see the dismantlement, or at least, carving up bits of the OE as a desirable thing, if only because they stand to gain from it. The losses in the Balkans are really a matter of time, the Ottomans simply can't win there; the question is how much they lose. At best, you can have a border a bit further west, and more islands in the Aegean. Possibly even Cyprus, though I doubt it.
The Middle East is a somewhat more interesting question. A significant part of Ottoman rule was the fact that it professed to rule from a multicultural identity (with varying degrees of actual implementation), which helped to bind Arabs to the Empire; the above also applied to the other religious and ethnic minorities of the Empire. Somewhat more material, however, was how the Empire professed to be the ruler of all Muslims; a claim, which, of course, was never completely fulfilled, but which one might say is wide enough if you have all Turks and Arabs.
The loss of Libya and Tunisia to Italy both cements the decline of that ideology, due to the Empire's failure to have protected these Muslims from foreign rule, and the discreditation of this religiou authority in favor of nationalism. It's extremely difficult to prevent that; it's too far from the Ottoman center, and too close to Italy, and Italy is typically in a much stronger position, and has a better international opinion generally.
That, combined with Egyptian autonomy, means that Ottoman control over the Arab peoples is only a question of when. If the Ottomans survive WWI, often represented through a CP victory and Germany propping up the Porte, then their rule over the Near East gets a new, but ultimately, probably temporary lease on life. I really don't see the Ottomans permanently ruling the Arabian Peninsula, or even the Near East.
Now, let's talk about what the Ottomans can keep.
The rise of the Young Turks accompanied by Turkish nationalism will only contribute to the above, but it will also have the effect of cementing Ottoman rule over the Turkic regions proper. If the Ottomans push all the way to the Caspian Sea, they will bring the Azerbaijanis under their rule, and my understanding, which may not be correct, let it be noted, is that there was always some fondness between Azerbaijanis and Turks, based mostly on their closely connected national heritage. If Turkey absorbs Azerbaijan, it could well merge the Azerbaijanis into the Turkish nationality proper. If she dislodges Iranian Azerbaijan, the general region around the city of Tabriz, from Iran and absorbs it into Turkey, she may well keep it as well. In the hypothetical CP victory, while somewhat unfortunate, it is likely that nobody will remember the Armenians. Perhaps Turkey could even gain for itself a favorable border which contains Georgia, which was given to it after Brest-Litovsk. Do note that the same problems which plagued Turkey in Europe are likely to plague her here, but it does help that Georgia is far more removed from European powers than the Balkan countries. It is more likely, if not much. The other Turkic countries, in Central Asia, and Russia, remain a pipe dream, as ludicrous as Pan-Slavist ideology, except without the benefit of having a Great Power of the world actively pushing it.
So, overall, what I see is likely is islands in the Aegean, maybe Cyprus, maybe some minor revisions near Istanbul, and possibly the absorption of Azerbaijan, Iranian Azerbaijan, the lands in-between, basically pushing Turkey to the Caspian Sea. That's the most I can see for the Turkish core territory, which is really the only viable option, as I see it.