Are there any tracks in in the dust other than mine?
The towel could be extremely useful so I take it with me. Since this room is kept clean while the outside is dusty I assume there might be another entrance, so I go look for one, while also keeping my eyes open for power tools, keys and a charger. In particular I look inside and behind the fridge (should my rescue take a couple of weeks it would be good to know what my food reserves are).
I have plans for the snow shovel but first I'll try to exhaust my non-violent options.
There are in fact some tracks that do not belong to you. They're not recent: you saw them already when you first got upstairs. The tracks have been imprinted by heavy boots.
Taking a towel seems a good idea: a towel is about the most massively useful thing a pub patron can have. The shovel might be the second most useful, who knows.
That said, there's no other door on the first floor. There's a window, but it has the same window grilles as downstairs (plus, probably you don't want to jump one floor, do you?). The dust must come from the other door.
You search deeply for something useful for your evasion. No keys, no laptop chargers (well, you would be very surprised to find Isvarahparamahkrsnah's laptop charger in a private area of the pub!), and most definitely no power tools. Plenty of bartender stuff though! You see a shaker, a pack of wooden twigs for skewers, a fire extinguisher (safety matters!), aprons, corkscrews, books about cocktails, and more.
The fridge contains frozen food of course: plenty of sandwich bread, some packs of frozen chicken wings, frozen pizza: you're not going to starve, and you might even enjoy some aperitif. Moving the fridge pays off, in that you find some lost coins, and more dust of a different kind.