Here is the probability of a quarter-inch of ice or more.
Here is the probability of a 1/2 inch or more.
When amounts reach a half-inch, the likelihood of power failures goes way up. In the area with blue or rust colors, amounts will exceed an inch in places. This makes long-duration (a week or more) power failures possible.
Before departing, the type of precipitation is going to turn to snow. Here are the probabilities of 4 inches or more of snow.
Please scroll down for safety suggestions.
I'll have another update this evening.