Kosch, I viewed your pic. You have spent some time prewintering your hives, insulated and strapped, looks very nice, organized and on solid block foundation.
Pertaining to feeding, I have to ask about hive weight, are the hives light weight, just lift the back of a hive and determine if heavy or not.
A small dose of 2X sugar can go a long way if applied properly. A constant supply can iniatiate the queen laying which you probably don?t won?t in your area at the present time.
Don?t feed next to a hive or you will have robbing. Later, as the weather warms you can switch to 1X sugar, better in spring than 2X, but you must consider your honey if you plan on extracting the Honey. You do not won?t sugar or essential oils in your honey.
If you want to pamper the bees, feed some 2X sugar then as the weather warms you can conduct a more thorough hive inspection and make appropriate decisions at that time.
Blessings