It looks like the Sixers will be taking their talents to London next January for a regular season game against the Celtics, per a report from the Philadelphia Inquirer's Keith Pompey:
The 76ers are expected to host the Boston Celtics in a regular-season game on Jan. 11 at O2 Arena in London, according to a league source.
— Keith Pompey (@PompeyOnSixers) July 13, 2017
This would be a part of the NBA's Global Games series, which has held games in London's O2 Arena for the last five years in January.