In general, I'd say you shouldn't mess with new kit (at that level) unless you otherwise need to. Most suppliers are going to anchor the heatsink down more consistently than you can redo it (without your own prior experience, and if you were confident in this then you probably wouldn't be asking), because if they don't then they're probably noticably bad from all prior sales and had to recall and/or been visibly badly reviewed.
Yes, things might still go south months or years down the line, and if nothing beats the practiced hand that takes great care over whatever man/machine might have just slapped the original together in the most time-efficient way.
Also consider that laptops are tricky buggers (even without any intentional barriers to user-servicing) beyond the replacement of memory modules or drives (where strategic hatches or modular caddies are implemented) so I wouldn't be surprised if you had to remove the whole back to access the screw to remove the keyboard to unhook the screen ribbon-cable to allow you to shift the heatpipe-and-integrated-fan-housing, but only after undoing three or four other screws (probably beneath the keyboard) that tie it to the mobo and unclicking a further jumper-wire or three. Just one of the issues I have with laptops (acknowledging that it's often necessity due to packing rather than just awkwardness applied by design). But doesn't stop me (carefully!) diving into them where necessary. 'Necessary' is the key, though. YMMV. Caveat Tinkor.
(Sorry, no idea about hibernation. Avoid it at all costs myself, for historic reasons, but also haven't expunged it as an option yet. May look to adding that to my repertoire, when I can, but by then someone else will probably have helped.)