My 706 runs me in the coldest months about 30.00
I live in North Dakota and the wintertime temps can easily be -40 for days. My spa has nothing around it so it's completly in the elements. Most months my spa will run between 20.00 to 25.00 and in the summer less then that so it averages around 25.00 over 12 month period.
I have three teenagers and they're all in sports so my spa gets used almost every day by someone and some days several groups of teenagers and their friends use the spa. In fact some weekends that spa cover is off for 3 to4 hours and the jets are on the whole time as the spa gets fought over between kids.
As far as the filter. Did you know the big filter in your Coleman will last you years. Because of the skimmer basket catching debree like twigs, grass, leaves, hair scrunchies,tree seeds,and other crap that blows in the water, you don't have that tearing up your filter. The first filter that rests on top of the skimmer basket is semi disposable in that you can use it till it starts to really lose it's shape which will be months and months of use. After that we sell them two to a package for 16.00 You may buy two at the very most per year.
I really consider my spa useage extreme due to my climate and teenagers. Most spas are not put in this severe of an enviroment,
Spahappy