If you are plugged in, the battery is irrelevant.
If you are not plugged in, you can only run the 12V stuff without an inverter (so no AC and no microwave).
100 amp hours should get you through one night with the fridge, some fan or furnace use, lights and some TV.
Not sure how good the WFCO charger is. Getting the battery to full charge is very important and many of the converter/chargers do not do a good job. This site has an article on the Progressive Dynamics converter charger.
As a point of reference, I have 235 Amp Hours of battery and overnight with temperatures in the 30s using lights, some furnace, propane fridge (uses much less than compressor fridge) water pump, Ipod speakers, I wake with about 90% batteries left. This is really 20% of the capacity used since you should only discharge to 50%. For your 100 Amp hours, this would be more like 40% capacity, but I bet the compressor fridge alone would take 20% of your capacity or more.
If you are plugged in all the time, it’s a non-issue. If you plan to live overnight on the batteries, invest in a Trimetric battery monitor so you know the state of charge and don’t kill your batteries.