I need help migrating my Lightroom Classic library to Lightroom CC

[phototocanvaspdx]

So Im considering switching from Classic to CC as I do a ton of editing on my ipad. I like the idea of my photos being in the cloud (full res). But I will still occasionally use Classic. 

So far the info I have found has told me to simply migrate the catalog to CC. I already have all my images in Classic in collections. This will simply upload them to the cloud. 

Now my question is on local storage. One person mentioned that when you open Classic, any synced collections will be dowloaded locally. Within the preferences there is a spot to select the location, and even the folder structure. I like this. So there is also a local option in CC. Should I have this turned off to avoid doubles locally? Or should I not let Classic do it?

I tried exporting a small folder as a catalog to test. The thing I don't get, is when I opened classic back up, the images all doubled in the folder within Classic. If I use my finder, the folder shows just single images. 

My plan was to open Classic, let them download to the new folder structure, then erase the old folder. If there is a way to not redownload images that are already on my hard drive, thats ideal. I have 3 TB of images and that will put me over my data cap with my ISP. 

Thanks for any tips on this workflow!

[Jao vdL]

And it doesn't matter if you set the location for your photo cache in Lightroom Cloud to a different disk. You are still limited by the startup disk. It's a really limiting thing for heavy users with large catalogs in Classic that want to migrate over to Cloudy.