I wouldn't use them or even give them a try.

quote right from their website under the listing for the "green cups" it states

These cups are designed to compost in 45-60 days.

That's 1 1/2 to 2 months and are compost history.

New England winters are a heck of a lot longer than that, and if you go south the heat could and no doubt would compost them a lot more quickly.

I've been using cups and reusing the same plastic ones for more than 8 years now and still have plenty of them along with some styrofoam ones to reuse.

Fran