Northstar is supposed to open, as well.
Right now it really depends on the weather and whether or not the proposed storm that's been hinted at coming in today and tomorrow hits and leaves behind any snow.
The best advice is to go to the resorts websites you listed above and look at what they have open.
Pretty much all of the resorts that are open have minimal terrain and what is open is a very minimal base of man-made snow.
Last time I looked the run open at Rose was a "Magic Carpet" run (i.e. really super dinky bunny hill). I've heard that Boreal has 2 lifts running, one for the park/terrain, the other from the top, but again it's primarily man-made WROD.
Kirkwood's site says they will open depending on how much, if any, snow falls during this upcoming storm.
The "best" option may very well be Mammoth, but that's a haul.
Again, you will probably be best served checking out Heavenly, Boreal, Rose, Squaw, and Northstar's websites to see exactly how much terrain will be open as all of those resorts will have pretty much the same amount of coverage, give or take (again depending on the storm and also how much they've made snow).