I’d suggest looking into bib tights. For “real winter”, I find them far preferable to waist high tights. They are too hot for spring but for winter, nothing I’ve found is better. I have a bunch of Pearl Izumi and some ones from Performance/Nashbar. You can find all kinds of them with weather proofing but they are kind of expensive. They last forever but the initial cost is a bit high.
I also have found that I can get good deals on the ones with chamois on clearance. It trivial to remove the chamois. All you need is a seam ripper which is just a couple of bucks at a fabric store. If you are unclear on how to use one, ask the people at the fabric shop.