I actually have a nice set of Trek full shoe covers in size 47-48 that I will sell you at a very good price if interested. I bought them hoping I could squeeze my 49s into them but they won't quite fit. PM me if interested.
I used toe covers last year, they kept falling off when walking around. Full shoe covers are not much more expensive, don't fall off and if you buy them large enough they allow you to add some closed cell foam insulation pads for extra warmth.