Is it possible to export multiple collections to a new catalog?

I have an original Classic catalog with about 40k images, most of which are several years old. During those years, my workflow was to simply upload photos from the SD card and dump them into LR Classic, without much culling or rejecting. 

Fast forward to today. I have decided to use Lightroom (cloud) as my primary editor and DAM program. As such, I want to migrate my Classic catalog to Lightroom, so that all of my images are in one place. However, I don't want to migrate all 40k of the images, since many of them are not keepers. Instead, I only want to preserve the selects in that catalog, which are currently organized into collections. 

I've done some research, and it seems the best way to accomplish this would be to export the collections of selects into a new catalog, and them migrate that catalog to Lightroom. However, I'm unsure of how to do this in a way that preserves the organization of the images in their current collections. I have about 25 collections, and each has hundreds of images in them. If possible, I would really like to avoid having to reorganize them into these collections once they are in the new catalog.