[I'm doing this just for fun!]

Hello there,
Please excuse my bad English, my noobity "if that's even a word" and my long topic

I recently managed to edit a Python code which generates random WIF private keys one by one and I made it create more and store them to a text file
It generates up-to 10,000 per second on my i5 laptop
I'm doing this just for fun!
Anyway, I created like 100,000,000 random WIFs and stored them in .txt files 50K each "Because I read somewhere it is the electrum limit to avoid freezing ... etc" ..
Unfortunately, Electrum is extremely slow and this may sound like a joke, but it is moody sometimes  [In best cases it imports like 10K every like 15 minutes!]
So I thought about using Bitcoin Core since it sounds faster to import these WIF as I have read. I wanted to download it but it is like 350 GBs! and also I have to upload like 5 GBs daily and daily updates ... etc! That sounded like a real problem not only for my bundle but also to the space on my hard drive  I mean It's like giving away almost like half of my half drive not to mention the time it will take to be downloaded which is like 24 hours according to my connection speed and the daily consumption of my standard bundle which is only 250 GBs per month
- I would like to know if there is any possible way to import all these private keys without downloading the whole blockchain?
- How long it will take to import let's say like 1M WIF? and how much data does it consume?
- Will importing using Python will make it faster? if yes, please suggest a useful tool for that with an explanation for it.