The large producers have to tap early. When they have 40-50k+ taps to put in it takes weeks to fully tap all the trees. They all use fully sealed vaccum systems which largely eliminates bacteria contamination in the tap holes. This alows them to extend there season and also get sap under marginal conditions. For smaller producers it's not worth it, you'll get a run now but it will inevitably get cold and the taps will dry up before the real season even starts. I tap a few trees, but always wait until atleast Vday.