FWIW after reading about the Intel NUC's ITT, I actually bought one of the higher-end models (i7-10710U / 64GB ram). My previous setup sounds like it was similar to yours: high-end gaming laptop w/ 32GB running 2-3 external monitors...wanted to know what I was missing by having 32 instead of 64GB. Answer seems to be not much. I'd say performance is a little bit speedier / snappier on the NUC, but nothing dramatic. Heat issues haven't seemed to be an issue thus far with the NUC, which was a concern given small form factor...I guess I wish I'd bought it instead of the laptop since it was like a third the price.
Hm, might have to amend this: I sat back down yesterday (after ~2 months of using this NUC without issue) to find that the machine had apparently rebooted on its own, and there was a black screen like the below saying "System has recovered from an over-temperature condition."
Quick google search found many other threads about NUC and heating issues. Not saying that it's a pervasive problem with the line, but given the form factor, it's the issue I and others were concerned about ITT and it doesn't augur well that this happened after only 2 months of use.