Which UGQ underquilt to pack?

[Vulture]

I just used my new set of 0 degree UGQ topquilt and underquilt at a not very cold hang. It was very toasty and definitely overkill for 20 degrees, windy, and humid (freezing rain then snowing). I'm expecting to get a 40 degree set soon. I'm wondering how you decide on your insulation to bring on a particular hang based on the forecast. Err on the side of warmth?

[CooOkieCOOon]

I'd pack for at least 10° lower than forecasted weather. Better safe than sorry.

[breyman]

I try and err on the side of having something 10-15 degrees below the lowest I expect.

[Bubba]

I'll always err on the side of warmth. Nowadays the weather seem more unprediictable than it used to be. Yesterday we had a 12*C daytime followed by a -13*C night. I'd rather be too warm and have to vent my insulation than be too cold not able to do much about it.

[Vulture]

I'd rather be too warm and have to vent my insulation than be too cold not able to do much about it.

I had to vent quite a bit. We haven't gotten anywhere near the 20+ below we used to get here in Michigan. Lowest so far is 16* below in my back yard. Looks like it's cooling down though. I'd like to put my UGQ Zeppelin to the test.