I haven't had this problem, nor will I (my mom died at 55, suddenly, and I won't be helping my dad out should he have such problems), but I watched my mom go through it with her two sibs, and little dribs and drabs of it area happening in hubby's family (also a 3 sibling family).
Honestly...it seems that with 3 siblings, there's ALWAYS going to be one that either is a slacker (my husband's sister) or is *perceived* as a slacker (my aunt went back and forth on who she considered worse, her brother or my mom). And it's really REALLY hard for each side to TRULY understand the other side (my sister in law's a flake, but I'm sure she FEELS she has a different reason).
I would be cleaning it out now and not wait on siblings. I would not wait until Feb to clean it out when it needs to be market March 1st.
Yes.
It's really a tough situation all around. Two of us (me, and the vacation sibling) live too far away to help out before hand. We've also taken way too many days off work during the past two weeks dealing with our mom's hospitalization and move into the assisted living facility.
There will be a lot of bad feelings while two of us are spending 9 days doing all of the work, and one of us (and spouse) is in Mexico.
YOu will be one of the people having bad feelings; and all you can do is work through it. My aunt made herself absolutely, positively, miserable for well over a decade. She first lived with my grandma b/c they had to, post-divorce, then as my grandma started to go into Alzheimer's-land she needed to stay there, then at long long last my grandma broke her hip, was in a nursing home just a bit too long, and her reverse-mortgage kicked in, and then she was the woman-on-the-scene for all of that. My mom, who was still alive at the time, went down to help with the stuff-moving (grandma made things SO easy, because for upwards of 20 years she had been marking EVERYTHING with who it went to), but my aunt still considered it to be too little. The money my mom sent was too little (she had two kids in college or grad school at once!), the time she spent was too little, etc etc etc. The reality was, my mom did what she could, when she could, she sent what she could, and she couldn't have done more. My aunt STILL doesn't feel that that's true, even though my mom isn't around anymore (she got all this stuff from her mom, and not too long after died and I inherited it all, ugh) to yell at about it.
My aunt should have taken the time to let it GO. She was the oldest, she knew the faults of her younger sibs very well, she should have expected to never be satisfied, and just let go of the bad feelings.
So really, all you can do is be chipper about it all. If the vacation-sib was there, they'd probably be bummed and not work as hard, and maybe you would still be peeved.
Maybe that sibling can send a bit of money along, to hire someone to help with the heavier lifting, or can get something else (a load of plastic bins, or a dumpster, or whatever you need). Maybe that can be their contribution instead of sweat equity.
If you've never seen a post about people DESPERATELY needing a vacation after dealing with some big bad health thing with a parent, know that many people feel it's OK to take a vacation after something like this happens; it can save your sanity. I'm really sorry you don't get to take the vacation, but maybe it's something your sibling absolutely positively MUST do...