Old winter onions

Hi
I bought some winter onion sets at the end of October but was unable to plant them due to numerous crises! I am now in a position to plant them, but the pack says they should be planted by December. Should I plant them now, wait till March or buy some more?
There are 3 different packs, they 've started sprouting in the cupboard, and there is a slightly spiffy onioney smell coming from them. They are a little soft,  although one pack has stayed firm.
Please advise!
Cheers
Steve

Thanks Yorkie
Got loads of space, so here we go!
Cheers
Steve