Temperatures here have been dropping to below freezing in the morning and around low 50's during the day but my average MPG's have been increasing.
I have installed a DIY brick edging lip (different than the usual home depot lip) and an EOC ignition cut off switch.
My results show an improvement from 50.2 MPG average per tank up to 50.6 MPG per tank over the last 10 fill ups.
Its starting to look like this car will be parked for the winter pretty soon but I am optimistic that I will be averaging in the high 50's and low 60's by summer
As you can see from the graph I have a pretty steady MPG improvement from June of 2014 until now. mostly based on required mechanical repairs and the use of a new wideband O2 sensor, new tires and EOC