Is an s21 still required for a fixed term tenancy- one year in our case? Oh yes, absolutely.
So basically we could wait until near end March 13 and then say we haven't been given notice? Yep. You are completely within your rights to sit down, put your feet up and completely forget that any of the previous conversations/emails/memorandums took place. As of now, you have not actually been given notice to quit.
When March 13 comes around and they want to know when you're going, you say "Going? But I haven't received the S21 as required by law yet". Then watch them run around like headless chickens.
Your biggest problem is the reference - you do need that to rent somewhere else.
So, here's what you could do:
It gets to 13th March and you're still there. They realise they need to then give you 2 months notice which will require possession after 25th May. An S21 is NOT NOT NOT a notice to quit the property - it is a heads up from the landlord that he requires possession after a certain date and will take legal steps to get it if you remain. Of course, most people do go, but there's no obligation to do so.
Your landlord cannot end the tenancy by himself - only you or a judge can do that. So, the law allows you to stay put after the expiration of the notice & wait until such time as a judge ends the tenancy.
All of that takes quite a long time - at least a month to get before a judge (taking us to 25th or so of June), you'll be given 2 weeks notice by the judge to get out (so around mid-June) and if you STILL don't go, then bailiffs can be appointed to physically remove you and that will take at least another 4 weeks (rarely shorter, but usually much longer). This takes us to mid July-ish.
I am not suggesting you follow things through to the bitter end like that - but you COULD do, and it's entirely possible that, perfectly legally, you could stay in the property for another 6 months or so.
They won't be happy about this, so you could say:
"Dear Mr LL/Agent
As I am sure you are aware you were legally required to serve me with a Section 21 notice. You failed to do so, so it may be that I have no option but to exercise my LEGAL RIGHT to remain in the property until my tenancy is properly ended by a judge. However, I am willing to overlook this rather serious breach on your part and move out at a time mutually convenient to us both in return for a reference from you that properly reflects the exemplary way I have maintained my tenancy".
Or words to that effect.
Whether this is a path you want to pursue is up to you - but the fact remains that you can if you want to.
:)