Breitenreiter threatened his squad with extra training over Christmas if they failed to meet his target of four points from their last two league games of 2018.
The team fell short after drawing 1-1 with Freiburg on Wednesday, and then losing 1-0 to resurgent Fortuna Duesseldorf on Saturday.
They are now second from bottom in the table with just 11 points from 17 games. Only goal difference keeps Hanover from last place in the league, currently occupied by Nuremberg.
Although Breitenreiter has reneged on his Scrooge-like threat to scrap his squad's Christmas, he has still called them back in for training on December 28 - a full week before most of their German league rivals.
"We have achieved the goal of reuniting the team as a unit and I am also giving up my holiday to shake off 2018 and make it better next year," said Breitenreiter after a 45-minute session on Sunday.
"The situation is difficult for all of us, but if we take the right measures and stick together, I'm optimistic that we will stay in the league," he said of his relegation-threatened team.
The head coach, who is danger of being sacked by president Martin Kind, has however granted exceptions to Brazilian defender Felipe and midfielder Walace who are allowed to return on January 3, because of the huge distances to fly home.
Their record of just two wins from their first 17 games, including four-goal defeats to Bayern Munich, Borussia Moenchengladbach and Eintracht Frankfurt, is the worst start to a season in the club's history.
"It can not go on like that," said team manager Horst Heldt, who is under pressure to strengthen the team during the four-week winter break with striker Niclas Fuellkrug facing knee surgery and ruled out for the rest of the season.