Last year I hiked in the less aggressive version of Garmont Momentum's, and I believe they are insulated to 15 degrees.
Needed to upgrade because of my orthotics so this year so I went with the Garmont Momentum
SNOW VERSION. Insulated to -35. Got the men's version for I believe Amazon at a nice price. The web link here is from Campmor. If you are looking, keep in mind the key word is
snow because Garmont has several winter boots.
http://www.campmor.com/garmont-mome...i_sku=15343BLK7.5M&ci_gpa=pla&ci_kw={keyword}
Never had a problems with the ones I wore last year but wanted extra insurance for very low temps.
Wore then most every day when hiking with Molly and I had Hillsound Pro crampons on for several months. Someone helped me to adjust them properly and I was good to go. Because it was so icy where I hiked I didn't take them off 'til spring. My feet were never cold.
Why I went with Garmonts is because they are light as feathers, super comfy, give great support, have many 5 star ratings, and the first time around I had to really search because they were all sold out. That is a very good sign. First became acquainted with them on VFFT and never regretted buying this boot. In fact come warmer weather, I recall feeling sad because I had to put them away for several months.