I’ll bite. (fully realizing that you’ve acknowledged the diet/exercise thing.)
So I know a guy that got cool sculpting done. He’s a vain, racist, a-hole, but that’s not really relevant. Anyway, I read a little (ha ha, totally got sucked into article after article) about the procedure since I was curious when I heard he was doing it. So I have some thoughts, but only the variety to indicate this couldn’t be done at home with ease.
There is some vacuum action to draw the fat cells toward the cold. Idk how you would achieve that at home. There is some kind of protective sheet they put between your skin and the cold source, to protect your skin from damage, so a DIYer would need to get their hands on that. Ice packs come out of the freezer at colder than the temp range you indicated, so it will be difficult to know when the ice pack is at the right temp, and how long it will be at that temp. Given all those issues, i don’t really think you can replicate the procedure at home.
Also, there are documented cases of coolsculpting recipients that had some weird side effect where fat comes back the the treated site in and it is all lumpy and hard. That sounds awful. And idk if this has been studied in relation to cool sculpting, but there is a study indicating that a majority of traditional liposuction patients gain back all the fat they had sucked out, except in different places. So, say you get liposuction on your thighs... a year later, your thighs look great but your abdomen and arms are carrying all that lost fat. Basically I think you really can’t trick Mother Nature. Your body is made to defend your fat, it’s the body’s emergency savings fund. So not only do I think fat freezing can’t be replicated at home, but it’s also a bad idea to get it done professionally. (Not that I’m trying to convince you not to do it, I saw that you never would. Just making a statement about it in general.)