For many people the holidays are not "the best time of the year". For people who have lost a loved one, it actually triggers the pain and grief even more. This is not surprising since it feels like everywhere you look there is advertisement for family coming together. The truth is the pain can be unbearable and some find a hard way to figure out how to try to cope with the holidays.
The below links are a very good list of ways to try to incorporate your loved one in the holidays. The biggest thing I can recommend is to have a plan A and a plan B. It is hard to predict how you will feel the day of and having a plan in itself helps make the grief slightly more manageable.