I really cannot understand why Utd fans would be in favour of a winters break, though might be different in the future. For a start I don't think a winters break would have any real difference on players fitness, which is more to do with the competitiveness of the league compared to others. I having nothing against having one, as long as two key points are agreed. Firstly, this mustn't have any effect of the Christmas & New Year period which is on of the most exciting periods in the calendar, & as entertainers (presumably) footballers should be in the forefront of entertaining the public during the holidays. Secondly, a break means a break, & doesn't mean clubs send their teams half way around the world playing lucrative tours. Any that do this should have points docked.
The real winners would be teams like City, Spurs, & Liverpool due to the pressing/intense styles they play, & would certainly gain from a break. Whilst the losers would be smaller teams & funny enough us as Mourinho's sides hardly break sweat compared to most of our rivals, so would lose out. When I mention this might change in the future, is if we actually had a manager using intense tactics like Man Utd teams of old.