The earliest in at least 21 seasons:
http://www.spiritone.com/~kepler/stats/pts_above_500.html
I filled out the rest of the table. Game 13 is the 7th earliest in Cornell history that they have gotten to +8 in ECAC play. It is the earliest since 1972 -- 30 years ago.
Both stats tables, available on the Curiosities link on TBRW?, now date all the way back to the beginning of ECAC play. Kinda gives you a sense of what it felt like to wake up everyday with your team ahead of the pack. :-)
Note on the other table, http://www.spiritone.com/~kepler/stats/pts_per_conf_gp.html , that this is the 6th most points Cornell has ever had after 13 league games, going all the way back to the perfect 1970 season.