I have a 2014 Skoda Octavia III estate.
My problem is that the heating apparatus is not blowing air into the cabin.
Since i filled antifreeze 2-3 months ago it hasn't drunk a single drop of it, is this to be expected or could it be related to the cabin heater issue in some way?
My car doesn't drink a single bit of antifreeze. It was filled 1 year ago at manufacturing time and haven't needed a refill ever since. Yet I still have perfectly functioning blower with cold/hot air into the cabin.
In fact, this is true of all of my past cars as well: not one of them was drinking a bit of antifreeze and all of them had perfectly functioning blower. In fact, my last car had the coolant never changed in the 5 and half years I owned it, and it did not need to be topped up.
I don't understand why drinking antifreeze would be required for blower working. Certainly it isn't operating on using antifreeze as a fuel!
Your blower motor or some kind of control circuit is probably broken. You could start from checking the fuses, as they are easier to replace than the blower motor. You did not specify whether your car has an automatic ventilation system or a manual one. In automatic system, the control circuit could be broken; in a manual one it is possible the resistor is broken.
So, I have identified at least three reasons:
Investigate these and come back later for more help if they didn't help.
Assuming the fan isn't blowing any air at all then the first place to check is the fuse for the cabin fans. If it's this then it could be a simple cheap fix of just replacing the fuse (although this obviously depends on what killed the fuse in the first place!)
Now I'm not sure what (if any) differences there are in this system in the Mk III Octavias but the Mk IIs with Climatronic were notorious for blowing the "resistor pack" that managed the fan speeds. Unfortunately these aren't a particularly cheap item (around £100 from a dealer if memory serves) so you'll want to check the fuses and the actual fan motor unit first - the fan units can be removed relatively easily and once it's out you can try turning it by hand to see if it's gotten clogged up (which is another common cause of this - at least it was on the Mk II) and also you can wire a battery to it by hand to make sure it will run. If the fan motor itself is known good then the resistor pack is the likely culprit.
EDIT: Forgot to address the coolant (antifreeze) part of the question:
If we are talking about the fan not working as opposed to it blowing air but that air never being hot then the two are almost certainly unrelated. As others have mentioned coolant is not normally consumed and in normal operation the levels shouldn't drop noticeably in that sort of time, I'd be more concerned if it had used some!