Interesting mix of responses. I would sit tight, use Ibuprofen, strap the ankle, drink plenty including some warm drinks, check my phone signal frequently (it can swing in and out randomly) and rely on the fact that I had good kit, fuel, adequate water supply (the snow) and a supply of food/snacks.
Worst case scenario - It might be a 2 day wait until I didn't arrive back home and it triggered the alarm so it begs the question, what else could I have done as preparation for such an event ?... Maybe took a flare ? or maybe had a buddy GPS system (can be incorporated into mobile phone GPS map programs) where a buddy can track my exact movements (or lack of them) on a map on a computer via the internet. No distance covered in daylight hours in 3 or 4 hours = potential issue.