Candy board, fondant slab or dry sugar on newspaper — which one for an Ontario winter, and when does it go on?

Ontario, second year, three colonies. Last winter I did nothing above the crownboard and got lucky. This year I want emergency feed in place before I need it, and I've been reading about three different approaches that all seem to have devoted followings. Dry sugar poured on newspaper over the top bars — the mountain-camp method. Free, absorbs moisture, but I've read the bees sometimes just carry it out as rubbish. A poured candy board — a wooden rim with a hard sugar cake set in it, which doubles as insulation and a moisture sink but is a project to make. Or shop-bought fondant, expensive but a five-minute job. Questions. Which of these actually gets eaten in a cold Ontario January when the cluster can barely move? Does the feed have to be in direct contact with the top bars, or will they come up through a hole? And when should it go on — now, or do I wait until a January thaw when I can see they need it? Part of me says put it on now and stop worrying, but I don't want to encourage them to eat through it in November when they've still got their own stores.