According to sudies completed by Tim Wilmot at the UVM extension service, studies have shown that total sap collected over the season is about the same whether you tap early, as in the end of January, or at the more tradtional time of March 1st (see link to study below). Tap holes do not "dry out" in 4-6 weeks as some believe, but they do start to to fill in with bacterial growth when the weather warms in late March and April, and sap flow slows as a result. If you tap early, you will catch the early runs, but if you like boiling when the temps are warmer, there may be a little less to do. The bottom line is, if you think that there will be early runs, go ahead and tap.
http://www.uvm.edu/~pmrc/tapping.pdf
2015 - 40 buckets w/ drop lines
275 oil tank evaporator
2x4 flat pan
made 5 gallons!
2016 - 90 buckets
same evaporator and pan
hoping to make 12 gallons
2017 - 85 taps on vacuum w/lunchbox
50 buckets
Smoky Lake 2X4 drop flue pan