How long can soup be frozen for?

After halloween the pumpkins all seemed to die out, but at christmas i was wanting to make a pumpkin soup for starters, so i was thinking about making it now, i heard that you just add any cream in when your re-heating it. So what I was wondering is how long can a soup be frozen for? And does it need defrosting or do you cook it from frozen and just add a little water? Thanks