This is best handled in the Lufthansa forum, since we focus very much on how BA works and responds to EC261 claims. But given the weather in Bavaria and Austria, which I presume was obvious to you, then the airlines may well have a basis not to pay compensation, but nevertheless are due to pay right to care expenses as outlined in the top of this thread. I can see that OS and LH cancelled more Heathrow flights than any other airline on 19 February. Airlines typically do pay for emergency clothing and cosmetics in this scenario, just keep the receipts and photo them to keep a record. It does sound like a bad experience, but having had a few examples like this over the years, it's a fairly typical experience in those weather scenarios.