hey vastman . . . you're a good son.
Back in April this year, I also found the need to duplicate my Sonar set up onto a laptop to become more mobile with everything. I'll be interested to hear how you like the gaming laptop you're looking to buy, and how it runs Sonar.
I looked at that one too, but went with something not so much tailored towards gaming, but rather more of a "business class laptop" (spending way more money) hoping that it would last longer and be more stable, and most importantly, better cooling, less fan noise etc . . .
As far as migrating samples, VST's, and all things Sonar, I'm not sure there is a lot of choice, since many of the ones I have required re-installs . . . but fortunately I didn't have to do many GB's of downloads, as I still have the download files stored on other drives. You mention Omnisphere, for example . . . so far I've had to re-authorize that many times for some unknown reason on my laptop. The Orange Tree samples files for Kontakt can of course be just copied to your Kontakt folders, so that's easy to do. Sonar was the easiest install to accomplish with Command Center, 20 mouse clicks and a pot of coffee, you're done.
Yes, it's a great opportunity for VST spring clean, get rid of the junk, keep the "go to" ones.
One thing I've found is that some of my desktop Sonar mega projects kinda' choke on the laptop, there are some limits . . . but of course you know Sonar has workarounds for that.
Best of luck in your laptop adventure, it sounds like you already have it organized efficiently . . . and I might be a little jealous of your " 1TB m2 SSD" . . . I thought I would wait until they got cheaper, but I'm not good at waiting very long for such things.