my cat sounds very similar although she does still dart downstairs when it is din din time! she sleeps/lounges around most of the day, comes alive a little more in the evening (she'll come downstairs and plonk herself on our laps) but that is it really. i too have thought about it and put it down to it being too cold to go out. i have tried to get her to go out but she puts her nose up to the cold. i often wonder how she isn't bored out of her brains but i think she is contented and seems to love the (boring) way her life is. she does come alive here and there when i use the lazer pen, usually when dh is trying to get to sleep :D she has recently been to the vet for some treatment and seems (aside from her bad teeth and a mild heart murmur) to be in tip top shape (for her). perhaps go to the vet for an mot?
Probably because she's indoors more now with the snow, but she can't even be bothered to come downstairs for her breakfast unless I make a fuss! Also her pads are a VERY pale pink.........should I be worried? She seems ok in herself (she's 9 years old) so I'm just taking it that she's fed up (she has the odd energetic spurt, so I'm taking it as another sign of boredom!)