Hi Kathy,
(from apiary inspector, gardener, and beekeeper in NE Ohio)

BROWN/TAN SPOTS OUTSIDE HIVE
Honey bees try to hold their waste products internally so as not to soil the inside of the hive. They make cleansing flights, but usually not many are made when weather is below 40 degrees F. The spots that you are seeing on the ground near hives are bee excrement. It's normal to see quite a bit suddenly, after a period of prolonged, uninterrupted cold. The spots do not necessarily indicate a disease problem, like nosema. You could probably have your local apiary inspector test for that, if you have one. If there are deposits of dark brown excrement inside the hive, e.g. on top bars of frames, then nosema is a more likely possibility.

DEAD BEES
Bees die every day of the year within the hive, and surviving bees remove them to the outside. Some also die prematurely when they go outside and get too cold to return. As long as there are sufficient bees and food to keep the cluster warm and healthy new bees developing, then your hives should be fine.

You may want to check to see if they have enough food to last until spring. It will probably be at least April in your area before workers will be bringing in meaningful amounts of nectar from flowers. You can feed sugar syrup and/or pollen substitute to help them survive and build-up the population earlier. Your bee supply dealer and local beekeepers association can give you valuable advice and provide equipment.

'Hope this helps.

Here is a link that might be useful: Mid-Atlantic Apiculture Research & Education Consortium