If I'm reading it correctly...
12/23/2015 & 1/26/2016 -----------119 therms
1/26/2016 & 2/23/2016 ------------154 therms
Total for the heaviest 2-month period is 273 therms, or (x 100K=) 27, 300,000 BTU. Burned in an 80% efficiency furnace that delivered 21,840,000 BTUs into the ducts (the rest went up the flue).
Since you didn't share the ZIP code I'll use data from weather station KRDU (the Raleigh Durham airport) on
degreedays.net.
From the interval of 24 December- 23 February they logged 1336.1 heating degree days
So, your house uses (21,840,000/1336.1=)16, 346 BTU per degree day, or (/24=) 681 BTU per degree-hour.
The 99% outside design temp is 20F, the presumptive heating/cooling balance point is +65F, for (65F -25F =) 45F heating degrees.
The implied heat load is then 45F x 681 BTU per degree-hour=
30, 645 BTU/hr.
That's about right for a fairly tight 1500' + 1500' 2 story house with a fairly simple footprint such as a rectangle, not too many ells adding corners and exterior surface area. I would also expect that there isn't a lot of exposed above-grade foundation for the basement area for it to come in that low.
If you normally keep it 65F most of the time, use base-60F, and add another 3F to cover for the difference between 65F and the code-min 68F heating interior temp. Using base 60F they logged 1066.4 HDD, for
21,840,000/ 1066.4= 20,480 BTU/HDD or 20,480/24= 853 BTU per degree-hour.
The difference between base 60F and the 99% outside design temp of +20F is now 40F, but to meet code-min the heating system would have to be able to heat to 68F, so make that 43F heating degrees.
43F x 853 BTU per degree-hour=
36,697 BTU/hr
That's also a credible number for a house that size.
Unless you spent half of January on the beach in Zanzibar with the T-stat turned down to 50F or something, there's no way the design heat load is more than 40,000 BTU/hr. It's almost certainly going to come in between 30.7 -36.7K BTU/hr if you did an aggressive Manual-J.
You can fine tune it base on weather data from a station closer to your house, but that's unlikely to skew it more than 10%.
So, if you were going by the ASHRAE recommended 1.4x oversizing factor the optimal heating equipment would only need to deliver deliver 43-51,000 BTU/hr.
A single condensing furnace with 55,000-input would cover the entire heat load right on down to 0F without losing ground.
Yet your contractor was recommending a 60K for one floor PLUS another 80K unit for the other, more than 2x the capacity you would need even during the coldest hour of the past century, which is just plain ridiculous.
Depending on vendor & model, 2.5-3 tons of air source heat pump could cover a 35K heat load at 20F, with some resistance heating strip backup to cover for the Polar Vortex extreme events when the heat pump alone wouldn't quite make it.