I'd just Sta-bil whatever's left and don't bother draining it or filling it, then run it to full warm-up, then change the engine oil and chaincase oil. Then do everything else you mention. I'll add grease the chassis, do something to address keeping the battery fresh, coat all the exposed steel stuff with WD-40 or similar product, and try to store it someplace that's humidity controlled. Cooling system likely needs to be addressed somehow also...most sleds I own I just do a partial coolant change every year with a suction pump and never fully flush it to keep thinks mostly fresh, but a bunch here will probably disagree with my method.
But like every other storage question, there is no answer, and you'll get a whole bunch of different opinions. Some will say fog, some say don't bother. Some will say top of the gas tank to prevent condensation, others will say drain it or leave it nearly empty. And next fall all of our sleds will run just fine. Good luck.