Panel 1: We find ourselves watching Elly luxuriate in a nice, hot bath.
Panel 2: We next find her in the kitchen wearing her robe with her hair up in curlers smiling happily as she reads a magazine and drinks a cuppacoffee.
Panel 3: We contrast her having the sense to stay in with the family "stupidly" exhausting itself in the cold. As John wheezes for breath, Half-way Frostbitten Liz dunno why Mom don't come skiin'with them so that Human Popsicle Mike can say that she doesn't know what she's missing.
The joke, of course, is that Elly knows exactly what she's missing: being cold, getting tired, falling on her rump and, above all, bonding with her family. If she did something like this, she might get to know them as people and that would take the fun out of hollering at them all the time.
Summary: When one combines this with next week's week-long rant about heating the out of doors, the only conclusion I can draw is that Elly believes that her laryngitis is yet another assault willed on her by her family. She probably got it from a library patron but knowing her, she's going to blame her family's foolishness for her illness because unlike her, they're fine.
Also, if Elly were willing to get off her ass more often instead of sacking out and glorying in the absence of her family, it would have seemed as if she had a damned sight more time. It's not just her refusal to tolerate their behaviour that steals the moments away....it's her fleeing them lest she be dragged down to the status of "anonymous drone housewife wrapped up in her kids' lives."