Don't forget your cars - generally a great place to cache get home bags, a bit of food, warm clothing etc. Send out people in 2s and 3s to salvage what they can. Also browse through unoccupied offices for additional clothing.

Burning - even though the power is off, your fire alarm system is probably still on battery power. Watch your open fires, getting dowsed by a sprinkler system would make the experience far worse and more dangerous. Burning stuff would be difficult in a modern office environment, every trash can and recycling can in my workplace is made of plastic, not metal. And most floors are carpetted. The only metal receptacle I can think of in my workplace is the kitchen sink.

Communication - I work in a collection of 30 buildings, not in your scenario but there are likely others nearby in the same circumstance. Reach out, find the best shelter, unify your command with the strongest leaders, consolidate people, supplies etc. Put 1-2 people on a radio (you do have your wind up radio, right?) listening for intel, including storm status, what is happening outside your door. If you are stranded likely others are too, and as the storm allows someone will be coming.

Reach out - depends on the blizzard and how prepped you are, but you may be able to send out a party of 2-4 people to alert someone (local FD or police) to your situation and get assistance. Right now though this scenario sounds like that would risk lives, which isn't called for after a couple days.

Find someone with a Ham license, there's usually about 1 in 100, and hope they have a HT on them.

Medical is very important - a few who have diabetes etc may need to be specially managed and cared for. Poll everyone for EMT and similar medical training. Put the best person in charge of polling folks for medical issues that will require management. Mental health too - people are separated from their families and will become distressed by that. If you can do anything to restore comms (email, cell phone, landline etc) that may be the greatest benefit to the group as a whole, even if it doesn't result in your immediate rescue.

Know your limitations - you've been given charge of "living arrangements to get through the next few days", you haven't been promoted to lead the company generally. Beware of turning this into a Lord of the Flies scenario. Make sure you and your boss know your boundaries - he probably still considers himself to be in charge, but will accept your recommendations if they are logical and result in warmer, happier employees. He may also be turning to other employees for help, with or without your knowledge, and their assistance may conflict with yours. If anyone has been trained and drilled in DHS Incident Command, you will have an easier time of dividing up responsibilities with a central reporting structure if not actual leadership. You won't have to do everything yourself, you delegate folks for logistics, supply etc etc and give them tasks to accomplish. Whether my boss has taken the courses or not, I would probably have this talk with him early on as a way to organize and see everyone through. ICS gives a framework for addressing this scenario just like any other. And don't forget, if you can contact anyone else, another stranded group, rescue personnel etc, the next person through the door with more or better experience than you is probably the new incident commander - unless the next person is your boss' boss. Don't let your ego get in the way of shifts in command structure. New leadership is generally a sign of better organization and more resources to address the situation, things getting better.

Relax - blizzards will blow by. Modern office spaces retain heat pretty well, while they will cool down it will take several days to get pretty darn cold