Oh, bummer, don't think about winter yet, it'll be here soon enough.
Re the cover - keep an eye out for the yearly Camping World sale. Depending on your exact size, it may be slightly over $200, but you'll be getting a good quality Adco and they include tire covers during this sale at no charge. The catalog or online will tell you how to measure, but you can also just give them your exact make, model and year and you'll get the right one. Also, they will ask you where you're located since different parts of the country use different types of covers. Some folks do use tarps, but probably 99% of us recommend against it because it's not breathable and will cause scuffs to your exterior from wind. And, honestly, a large enough tarp to really protect your camper will not be all that much of a savings. We bought an Adco the first winter for our '07 ROO, which would have been winter of '06, and when it went to it's new family this spring, it looked practically brand new. So we had 7 good, functional years service.
Re the rest of winterizing - go ahead and pick up a couple of gallons of the pink RV Anti Freeze next trip to wherever you shop. Many of us use something to fill space in the filter cartridge canister, so something like the stones in the craft section or whatever you can find on the cheap will work for you. Make sure you have every bit of food and crumbs out of the cabinets so you don't invite critters. Actually doing the winterizing is not in my job description, so others will fill you in on that. Be sure to clean your refrigerator and make sure the door stays open. That's about the end of the project.
BTW, thoroughly read through the instructions with the cover before you start opening it up....there is a much easier way to put it on if it's not completely opened up. The cover is marked front and back and you'll save yourself a lot of frustration knowing this ahead of time.
