Well, in part I'm with Ram (hi again, Ram...). December now looms, you have not yet picked a boat, every boat for sale
is going to have some issues and be an unknown to you, and - in the near term - there is the as-of-yet unknown period needed to complete the sale
before the boat is put in your hands. (Remember: This is Europe
...even in Turkey
. Bureaucracy is an industry and, sorry to say, an accepted offer is unlikely to be followed by the boat's sale
in a few days). Summed up, my guess is that you will be leaving in January some time and, if you're smart about it, you'll start out slow with short distances through Greece
while shaking down the boat and addressing nagging, niggly issues.
To the extent that's an accurate guestimate of the reality of your plan, that's not the end of the world but let's remember its ~2,000 miles as sailed between moving aboard the yacht and turning the corner off Morocco
...so you're "doing" the Med in the winter. This isn't terribly uncommon but, as others have mentioned, you'll watch weather constantly and be making runs interspersed with periods where you won't want to be sailing even if you have a fair wind (which won't remain fair). Also keep in mind that the weather systems there are faster to change than we are accustomed to in the USA, and more complex & dynamic because the weather isn't just frontal in nature.
"Gonna be long, slow, cold and wet all the way to Canary Islands. Unless you are lucky. From there no problem to Antigua until June."
That strikes me as a fair summary except, even with luck, it isn't going to be warm. And the 700+ mile run from Gib (better, perhaps, if from Lagos) will require a special weather eye if you do it in Feb/March.
This will be the equivalent of 'work'. And plan on needing some time in Lanzarote or Gran Canaria or wherever, before departing for Antigua, to fix and service
and modify the boat, as the boat will be giving you a list you won't want to ignore before then next 2700 miles.
Good luck to you. And worst case: You leave a boat you are looking forward to sailing over in the Med for a spell.