According to dermatologists, everyone should use some form of sunscreen all year long. That is one of the reasons they now put it in much of women's foundation make up. So I say yes use it. Will you get burned if you do not ? No. I have gone at that time of the year quite a few times and before I started using a sun screen I did not get burned.
HOWEVER, bring a couple of sweaters or sweatshirts. I can remember twice the weather being VERY cold. You know how the stores at WDW pull out ponchos when it rains?? Well they pull out low priced wool stocking caps when it is cold. I had to purchase them for my kids and they even wore their pj's under their long lightweight pants for a little extra warmth. If you bring a couple of layers you will be prepared.
Keep in mind this DOES NOT happen all the time.