I have a WBRR- works wonderfully in three seasons. I haven't tried it in the winter yet though. My setup would be the RR, wrapped in my full-length Winter Lynx UQ, then wrapped in my WB Spindrift Sock. The only thing I have right now for top insulation is a 30* polyester fiber sleeping bag. The spindrift is said to keep wind out and stay 15* warmer inside. With a winter UQ, do any of you think that would be sufficient for weather touching zero? (It would be 15* inside plus the UQ). Should I invest in a TQ?