You should find that charity organisations will take the stuff unless it is soft furnishings in which case unless it has a kite mark they won't take it.
If I could offer some advice though as I was faced with a similar 'problem'? I bought a flat where the owner had sadly died. She had no relatives, the sole egregious lowlife of a benefactor for her personal effects simply came in, cherry picked stuff and then left the rest...including freezers full of food, fridge full of rancid food (probate took a year) and personal effects strewn about. It was all rather depressing. I was faced with having to clear out the flat and, like you, wanted to give away as much to charity as i could....clothes, furniture, carpets, curtains etc.
It was a nightmare. There was no one single organisation that would take the lot. I spend days and days researching, ringing around, waiting in for 'no-shows' and STILL I ended up taking suitcases full to the tip.
Never again.
Next time I will find a house clearer who will take the lot.. They usually pay a small sum of money for the stuff (as they can sell on a lot to make their profit). I will then give the small sum to charity.