Every so often, I buy a few cheapie frisbees when I can find them, the bigger the better. Color doesn't matter but they're good for all kinds of things where you need a quick container for pieces of projects you're disassembling, garden projects where you're sliding along the ground with a few packets of seeds, bulbs or whatever, etc. For my round shaped hanging bird feeders, it's not unusual that I replace what is usually a very small shallow seed pan/tray at the bottom with a frisbee type disc which keeps seed waste to a minimum since the disc has higher sides and a larger diameter.

We don't get snow often but it's quite easy to put birdseed or other assorted treats in an upturned frisbee style disc, set it on top of the snow (or even grass), and leave it until it's empty or you decide to knock off any accumulated snow/ice and refill. Easy to store, colorful enough to find easily, cleans easily when required, last forever (unless the dog finds them first and even then.... it may depend on the dog), and easily obtained at any store (dollar or otherwise) that sells children's toys or sporting goods. Probably a little easier to find during spring and summer months and definitely cheaper at end of season sales where I've bought the knock off versions for as little as 50-75 cents each. For wetter conditions, I do find it advisable to drill at least a couple of small holes in opposite sides of the discs to allow accumulated water to seep out. If you don't have smallish drill bit (1/16" or 3/32" is quite adequate), a heated #6 or #8 finish nail heated and then pushed through the plastic will work just about as well.

I would note here that the actual discs that are patented under the proper commercial/trade name are more expensive and while I'm sure they're far better made for the actual use for which they're intended, cheap knock off copies work just as well for craft and animal use since I haven't found a bird or animal yet that can read the manufacturer's name or object to the color of the disc.

As an alternative, an overturned garbage can lid will also work in a pinch as well as plastic 5 gallon plastic bucket lids (topside up) which also work even better.

Hope this gives you a few ideas to try.