Why do all the Lubavichers not sleep in the succah when probably none of them actually feel this tza’ar?
Who says that we don’t?
Sorry, but YOU have to find a source that tzaar that a person CAN fulfill the mitzva of sukkah is reason to exempt you from that very mitzva.
If it’s cold and you can bring in enough blankets to make it warm, but it’s too much of a shlep, you can sleep inside.
That’s why I feel like I’m going around in circles.