Unless you happen to be a lady Congress critter and have to go really badly.
It could get really important then.
Here’s an idea, for what it’s worth, why not make the existing bathroom available to either sex, just like we do at home? It would no doubt save enormous amounts of money as opposed to converting office space with union labor.
With 435 congresscritters plus their staffs using it, sharing one bathroom wouldn't really be feasible like it is at home. It's not likely that the existing bathroom has as limited a capacity as a home bathroom does. (I'd expect that it's got a dozen or more urinals and a few less stalls than urinals.)