Is it even possible for tablets to hold a charge so long and provide near instant wake?

Why didn't you try powering it off when done?

Of course it is possible. From fundamentals alone, it has space for a huge battery. Heck, many cheap laptops can sleep longer than a week and still has some power left.

I'm fairly sure my old ipad did, maybe the ipad air 2. My current ipad pro doesn't seem to work this way. I could be mistaken, perhaps I used or charged it more.

all of my phones hold a charge for 2-3 weeks in aeroplane mode with no installed apps. Even my 6yo phone with 6yo battery does. A tablet has a much bigger battery but not a proportionally bigger power drain when the screen is off, you might hope for months in aeroplane mode with no installed apps.

I have a very old samsung tablet that i still use from time to time. It never connets to the internet and wifi stays off. It can last easily a week or more on a single charge still. With wifi on, it dies within a few hours