No, you can't put a window air conditioner on the floor! It can be a fire hazard, and will probably drip, in addition to not pushing the hot air outside as it is designed to do. It needs to be in a window! What you need is a neighbor to move it for you. If neighbors aren't in close proximity -- you live in the country, right? -- how about calling your local church and explaining the problem? If they're anything like all the churches I know, they will send somebody over to do it for you at no charge. (Of course two baggies of cookies or brownies will be most welcomed -- one for the guy who moves the thing for you, and another for the church lady who answers the phone.)
My house is 110 years old, so the central air and heat are not good at all upstairs -- Central Illinois is like Missouri weather-wise, so I know what you mean! In the winter I use an electric blanket on the bed, and most of the summer turn on the ceiling fans. When it's simply ghastly hot and humid, I do use a pair of window air conditioners upstairs, one in a front window and one in a back window. As window units go they're fairly small, but still heavy! One winter I just covered them tightly with plastic bags and towels and left them in the windows -- not the best plan, of course, but it worked. Normally I have the window units in the windows only in summer, and the rest of the year have them sitting on those square, short plant stands with rollers, and roll them into nearby closets. I can roll the units right over to the windows and only have to lift them about 18".
I don't have a sewing room since I'm not willing to give up the second guest room, so I set up my sewing machine in the living room. The machine lives in a rolling case, and the sewing machine table folds and fits under the sofa. For cutting, basting, etc. I use a card table that hides behind a cabinet in the dining room. Since I use the sewing machine only occasionally, and only cut and baste once in a while, most things are stashed out of sight. Almost everything I stitch is completely hand-work, which makes for a lovely evening with the dog and the TV on the History Channel.