As I've explained in the "First World Problems" thread, I need to return the iPhone SE (2020) I'm currently using. Long story, I won't be missing it much, but migrating the data will pose a bit of a problem.
Now, the first option, and what I thought was the only option, was to back up all the stuff that I can via iTunes, and export WhatsApp chats separately. This way I wouldn't have access to older WhatsApp messages on my phone any more, but I'd still have them archived somewhere. Also, I could use an intermediate account for all the important messages I want to keep on my phone, as
@Matt2000 nicely pointed out.
The thing is, I might've come around with a workaround until I can afford a decent iPhone. (And I've looked at data plans, they'd all be considerably more expensive than what I currently have.) I happen to have a beaten-up iPhone 6 in my possession. It might not be much, but it has 64GB of storage (as much as my current SE 2020) and it's an iPhone, meaning, provided that iOS 12 supports it, I can keep all my WhatsApp messages, and all the other stuff that I need, directly on the phone. The downside to the workaround plan is, well, I don't know if iOS 12 is of any help here, and I'm not sure I want to daily an iPhone 6 for a couple of months.
Also, I'm still pondering should I stay with an iPhone or go back to Android for my next phone purchase. I basically narrowed my next phone choices down to iPhone 11 Pro and Google Pixel 5. (I know neither is new, but they fit my needs perfectly: compact size, decent camera, decent software experience, and they happen to fit my budget.) I got hooked onto iOS a bit, but there are certain bugs on my current SE that annoy me. Namely while using AirPods (which are another reason I want to stay with an iPhone). But then, I'm used to Android as well, and I'm tempted by unlimited Google storage. I know that's a decision for the future me, but it determines on whether I do the temporary iPhone 6 workaround or go straight back to my Huawei P20.