I know that people recommend having ARP for both Spring Break and Christmas, but I have no experience myself with this. Seems there was one renter here that ended up cancelling some Christmas dates because they didn't rent. Also, there is a mega renter that specializes in BCR.
For June, there is still some limited availability right now. So I would say you may not need APR as long as you plan 8-10 months out to get the room and times you want. Otherwise you may need some flexibility.
For Thanksgiving, you probably need APR. I've been booking this time for the past couple years. It's a high demand week, and there is very limited availability by the time 10 months comes around - very few units show up, usually just a couple 1 and 2 bedrooms, and they go fast. You might have some success if you aren't picky about the room or about getting a full week, or if are determined and keep watching for cancellations, or if you can be flexible enough to wait and see if a cancellation opens up around 15 days out or slightly before.