Split the 7 gallons between two fermenters. One was bottled on 12/9/18, while the other will be racked in secondary.
Based on boiling 8.70 gallonsliters at 1.049 for 60 minutes, this will decrease your wort by 1.00 gallonsliters, bringing your after boil OG to 1.055. You were planning on an OG of 1.055 so you are right on track. Nice job!