It's really kind of hard to say
CRO holds something like 4% of the inventory at each
DVC resort plus whatever they get into their inventory when members who own at that resort trade out for things like
DCL or II or what they obtain 60 days out from rooms that don't end up getting booking by members on points. They may have a 2bdrm and they may or may not have a discount for it in May. Ya never know. This past May, CRO had studio's with a discount code for Disney's visa card holders for $139 per night which was a great deal...it said on the offer insert that came with my visa bill "other size units may be available with the discount at varying prices". But CRO doesn't guarantee they'll have discounts out at any particular times. It's all hit and miss. I paid for my weekend nights this past May at Vero with cash via MS for a 1bdrm. It was $243 per night plus tax with the member discount so a 2bdrm would be upwards of that. I checked with CRO too to see which would be less $$ and CRO didn't have it available at all let alone with a discount. It was just as well because they linked my cash ressies to my pts ressies and I didn't have to move or check out and back in again.
You can also book cash via MS
if you are a member ~ It's all subject to availibility though. You have to call MS to see if
A. they have the size villa at the resort you want available for your dates and
B. if they not only have it available for cash but with the DVC member discount. Members get 25% off rack rates if and when MS has it available. Sometimes MS will have units available for cash but without the discount and sometimes they won't have it available at all....so cash ressies through DVC are also hit and miss. Plus MS generally will not make the cash rooms available until they feel those rooms won't be booked up with points so it could be very last minute as if they'll make those rooms available for cash at all.
You'd also have to call both CRO and MS to see who has availibility and if both do, who has the better rate

As for how far out can you make the ressies ....CRO if they have availibility you can book more than a year in advance just like making ressies at any other WDW resort. MS even for points ressies the earliest you can reserve is 11mos out for a home resort/7 for non-home resort and cash usually only a couple of months in advance if at all.
The other alternative if you want to pay cash for a stay, is that you can always of course rent points from a member for much less and it would be the same a points stay subject to points booking windows.
Hope some of this helps though
