I have only a few days/couple dozen journeys so far, but ...
I have created a spreadsheet that I'm keeping of my journeys [Note: Journeys from your car can be downloaded to a CSV file and emailed from within the InControl app (a darned nice feature!)].
In my spreadsheet, I use a chart of average monthly temp ranges against the date/time of the drive estimate the Temperature (which I could manually override if they were outside normal), and a formula against average speed to classify any trip as a city or hwy drive. I'm computing the energy used in those conditions. Using this sheet, and a large enough history, I will be able to give a good estimate of the expected range I should get on a given drive even if that drive is outside my "average" conditions (which is what the dashboard shows you unless you plan a route where the topology of the trip would intervene).
The point is, that as I get experience in different conditions/speeds, I will be able to filter my spreadsheet to "show me Hwy trips of temps between (say) 40 & 60 only - and it will estimate my range based on those times where that's what I experienced, and not from my overall average which could be from generally different conditions.
I will not get much experience in cold weather, however, where I live. So, I'd be happy to share my sheet with somebody else if they want to PM me, and provide me with an email. It's an Excel sheet with embedded macros - which automatically finds any TRIPS*.CSV file open (from an InControl email) and loads the data from it into your overall table of journeys. I promise you it's not going to infect your PC in anyway.
This kind of stuff is what I do for a living.