It is indeed possible to replace the frame and preserve the internals so your data will be there exactly as it was when you started.
Unfortunately, it doesn't seem there's a guide for your iPad available here on iFixit. At the risk of committing heresy by promoting a competitor, there is a complete guide to replacing the frame available over at the French site SOSav. Here's the link.
Frame iPad Pro 12.9 "(2017) repair - Free guide - SOSav
Of course, you'll need a replacement frame, but unfortunately I can't help with that, other than suggesting you check the big vendor sites. eBay would seem to be the best bet, as you may be able to find a non-functional one that can be used as a donor, or perhaps someone selling just the frame as parts. Otherwise, Amazon and AliExpress would be my next choice, followed up with a general internet search if you still haven't found one.
I've been in the same situation with my son's iPad, and fortunately after I had it disassembled I was able to straighten the frame satisfactorily enough that I didn't end up needing to buy a replacement after all.
EDIT: Had another thought for you; it's not uncommon for people to sell iCloud locked Apple devices, and I'm sure you could find one of your model. That would solve your frame and LCD issue both at the same time, and make the repair easier by only having to swap out the motherboard and the home button.
The drawback here is that it's probably going to be more expensive than just replacing the housing and display, but the repair being easier is the tradeoff. Or perhaps not; the LCDs being sold on SOSav were pretty expensive; i.e., $500-800 USD. Seems likely you would be able to find them cheaper though.
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