If you look at the way the word 'cold' has already been used in the novel so far, though, JA does mean 'unfeeling' in negative words when she uses it:

[John Dashwood]was not an ill-disposed young man, unless to be rather cold hearted, and rather selfish, is to be ill-disposed:

[Mrs. Dashwood's] eagerness to be gone from Norland was preserved from diminution by the evident satisfaction of her daughter-in-law in the prospect of her removal; a satisfaction which was but feebly attempted to be concealed under a cold invitation to her to defer her departure.

[Sir John] seemed really anxious to accommodate them, and the whole of his letter was written in so friendly a style as could not fail of giving pleasure to his cousin; more especially at a moment when she was suffering under the cold and unfeeling behaviour of her nearer connections.