All depends on when you want to travel but
DVC works better when you book farther out. Mid September to mid-January are the highest DVC demand times. People book their home resorts at 11 months and some studios and resort views are even walked. Traveling then will be difficult (like the OP found this year).
Summer? You should not have a problem finding something at 6 months out and may even have some resort options other than the big 3 of SSR, AKV, or OKW. Also will depend on how many nights you want too...getting a few nights is much easier than an entire week.
I have booked last minute trips before...3 to 4 months out...and found something, but I also was willing to split stay, waitlist, and stalk the website constantly. But, if the plan is to regularly not book anything until 6 months out and you want a studio, then there will be times it won't be easy. You may need to be extremely flexible with dates, etc. to make something happen.