I experienced great emotional (and financial) loss during a school remodel. I was a theater teacher and used to personally sew all the costumes for a show. To give you an idea -35 kids would wear about 90 different costumes and I made them all. In theater, costume changes need to take about 30 seconds so whenever possible you add to some base costume and keep it simple. We use magnets a lot for quick on and off. The only problem is that the costumes often have 3-6 pieces which only make sense to the costumer. Well the remodelers threw out about $20,000 (cost of materials) in costumes! I nearly lost it because that was also my art form and it was trashed in ignorance despite my thorough packing in plastic crates and labelling!
As for streamlining households ... I have done it more often than I care to think about because I moved so much. There are always regrets. When my parents passed, 63 days apart , and I had to make major decisions about a lifetime of memories, I followed this mantra. "When in doubt, store it for a year. " You can get rid of it later, but you can't get it back. However, you DO need to go back each year and look again and reduce it down further. In the end, I have what matters and peace of mind.
As for ski clothing ... I always have one aspirational ski outfit and one emergency outfit which is too big ... just in case ... because hope springs eternal, but you never want to miss a good ski day because nothing fits!