Did they all spray at the same rate as they did before you noticed your flamers incontinence?
If it's the rubber washer on the pumps then the water will only drain to just below where the hole in the bottle is, so the pump will still be able to pull water in. I wouldn't of expected the headlight washers to work though if it were a disconnect or badly, and it would have to be to piss out, damaged pipe feeding them.
It could even be that the pump is just not sat correctly in the recess of the bottle, just needs pushing down on it until it clicks in, so that could be worth a look.
Or, after all this lol, the bottle itself could be cracked due to the cold and need replacing.