Thankfully I live in a good spot it seems like, western Washington seems to have plenty of good options.
So, an update as I attempt to not to over think things - The hides I ordered finally shipped, but won't be here until next Thursday (the 7th). I was hoping it'd be sooner given that my thermostat from the same site arrived within two days of shipping, meaning I was also hoping to feed her by this weekend or by Monday at the latest.
Now it looks like if I wait, I won't be feeding her until next weekend. It sounds like that isn't a huge difference but it has me anxious, because I also hope she isn't losing weight in this time.
So my two options are either wait for those hides, or use the left over black plastic tupperware I still have, and this time don't cut them shorter but instead just put proper sized entrances and filled them some kind of filler to make them more snug.
To note, she has taken to the improper black hide shown in the previous picture pretty well for now, though I definitely understand how the big opening would make her feel less secure in the long run.