I put them on my personal vehicle at the last minute, and take them off as soon as I can. That being said, I do the work myself, don't have a "first responder" job, and the tools and other-season tires are usually already up in the garage beside the car weeks before I need them so a swap can be quick.
Despite what marketing says about 7C, I get better braking and road holding from my summer tires near freezing (in the dry) compared to any snow tires I've ever had - sport or not. I carefully monitor the 7 and 14 day weather forecasts for my area and anywhere I expect I will be going. If there's a risk of flakes or ice or a serious hard freeze then I prepare to get them on so I'm never caught with the wrong tires. In the shoulder seasons I find the temperature very peaky - when there's a cold snap it is usually dry, and then gets too warm for winter tires again for a spell.
All that being said, for others who depend on me to change for them, they get a more conservative approach, especially young'uns living out of town - they don't notice the drop in performance, have more unpredictable driving destinations and habits, and to them the car is an appliance and tires are round and black so they don't notice or care about any of the negatives of switching a little early. I am also the only one in the "fleet" I maintain who uses SUMMER tires in the summer. All the others are all seasons for the summer so, in reality, they aren't in as dire a situation as I am should a little taste of winter surprise them.
After a switch, the other tires and tools still remain in the garage for a little while. Once in the spring years ago I got a call about a family member health scare and I had to go out of town urgently. Where I was going still had light winter conditions persisting but where I live I was already on my summers for a week or so. I did a "pitstop" in the garage back to my winters in less time than it took for them to confirm which hospital I was going to be driving to.
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