Just to clarify (I’m not sure if this is what you meant) more ram will NOT improve multi-tasking while you render.
Modern rendering software will eat up 100% of the available cores. That’s why your computer will suck at doing anything while you’re rendering even if you have 64 gigs of ram.
I won’t try to sell you on the desktop, there are reasons to buy a workstation class laptop, as long as you accept the fact it’ll be an unruly beast.
Truthfully you can probably spend much less than that and get a burly machine.
Go with the fastest CPU you can spec (which you’ve done), the best display you can get (if you plan on working on the laptop display itself), a 512 gig SSD, and 16 gigs of ram. 32 gigs is overkill - I do work on gigantic assemblies and I rarely push past 8 even when heavily multi tasking with big databases and renderings.