I use the same TW/Burrow combo of 20 deg TW and 40 deg Burrow. It has worked well for me in everything I’ve camped in from 20 to 80 degrees.
TW is my favorite, but I do love the way down just warms you like nature intended with all natural insulation that has evolved over hundreds of millions of years! . I like having both depending on the conditions to use either or both and have not been lacking yet. Good luck.
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