Here's how long it has taken me so far-
1 day offer accepted.
10 days to pass ROFR.
13 days to get Estoppel.
2 days for me to sign contracts and wire money.
So so far it has taken nearly a month. Now I am waiting for the other side to sign contracts and closing. I hope that may take around a week.
I understand once closed I may be able to get my member ID by calling up in about 10 days, otherwise you wait about 2-4 weeks for the letter.
So realistically at the moment if things go very quick, I think you can wrap the thing up in around 45 days from the start. However, 60 days may be a realistic target.
As others have said you will have no problem finding somewhere for next January. If you wanted a 1 bedroom, at 7 months out the data shows that you could likely book virtually any resort 1 bed for Jan- studios more difficult but there will be availability. If you get going beginning of March, you should have your points by mid May, assuming not ROFR. I would then recommend immediately booking your home resort, and if you do want to try somewhere else, bang on 7 months out log on and try to switch.
If you do fancy staying somewhere else other than home resort in Jan, you need to have obtained your points by no later than begging of June so you can be on right at the opening of the 7 month window, so you need to get buying in March. A ROFR could throw a real spanner in the works as it will delay you by around 2 weeks, even if you manage to find another contract quickly. However, if you want to stop SSR or OKW or AKV it will not be so crucial to have that 7 month window- you will likely be OK around 4 months out at one of these.