I've been there loads of times NS, but the last time that I was home there had been a rock fall so folks were advised to stay away.
I often visit if I'm walking along the river, and I've stayed there many times. It's rare to have the place to yourself, as it's popular with groups of students.
Here's the entrance:
And a view from the inside:
You don't need to carry water up:
It's best if you take your own wood ( or coal ) though, as the area around the cave has been well gleaned for years.
I'm not sure about the current situation re rockfall, but if you give Needlesports in Keswick a bell I'm sure that they'll know the situation.
Cheers, Michael.