fh, it's not so much about cold and wind, it's about disturbing the cluster. sometimes in not so good circumstances placing feed in, in cold weather climates is tricky. that sugar should last them awhile. do you have an inner cover over the board? if so, on a warm day you can gently(lol on the gently) remove the outer cover and take a quick peek in through the hole of the inner cover. (i use a flashlight and cheaters....lol) not sure but i think beeks in northern climates will put a 10lb bag in and lasts until spring......lazy beekeeper may be able to answer this question for you better than i can.
about honey reserves, i use double deeps, as far as leaving the extra super on, only you will be able to guage what needs to be left on come fall or before harvesting any honey from a hive, and that applies to any time during the season. for example if the bees put away some honey in a super during the season and you hit a dearth, leave it on for them, then feeding them sugar syrup is minimized. if in late summer and early fall, there is not enough stores for them, leave it on for them, or what i do to get them to fill out the bottom deeps; i will place the super above the inner cover and scratch some of the cappings so that the bees move this down into the deeps below. one has to be careful with this though, so as not to set robbing off. i don't typically winter my hives with a super on top the double deeps. i do my best to see that the deeps are full. leaving a super on absolutely does no harm and is extra insurance for your bees. better for them than running out of honey stores.
hope i made sense? best wishes to you and your bees!
