It's honestly a bit rich for clubs to get to the latter stages of the cups and play in the CL, and then complain about fixture congestion. There's nothing stopping anyone bailing out of League Cup or FA Cup if it's such a problem, nor indeed the Champions League itself. Playing lots of games is what happens when a team is successful, and telling all the others, including lower league teams that things like FA Cup replays can disappear is pretty damned arrogant - I don't remember us complaining when we got knocked out in the 3rd round each year and had no European games. So it's all for four teams at the top of the league who have the most resources anyway, and stuff everyone else? Don't like it, don't try and compete in it - nothing's stopping clubs doing that, but of course they want to win, that's exactly the point.
The usual argument in favour of a winter break is that it keeps players fresh for World Cups and half the posters on here have said doesn't matter because they don't care about international football in the first place, and if so then it's purely self-interest that's driving it, nothing else.
So what it amounts to in a lot of cases is a complaint that City are a bit tired because they are playing lots of games. Well, yes. That's what happens when you're going for every trophy - we don't have to you know, we could put the kids out in the cups.
The big clubs have enough advantages as it is, without handing them even more. If it really is about the players, then don't drag them across the world on club tours in the summer, and don't disappear on money making jaunts the moment there's a week off.
Yes, absolutely there are things that could be done to help. But not because it suits City (or United, or Liverpool, or Chelsea, or Arsenal), that's a terrible reason.