You'll have to give me a bit of leeway here - I build a new PC every 5-6 years and have to relearn everything so I may say or ask something stupid in this post.  
 
ANYWAY - I picked up a 2080ti off the B-Stock.  I wanted to spend a lot less on my GPU, but given the market I'm just taking what I can get.  I came up with the idea to have the card mining ETH when not being used for regular use to hopefully pay for itself after a year or so (or at least mitigate the cost).  I started mining and pulled up a hardware monitor to keep an eye on it, and I'm seeing that the 2080ti is running at 85-86°C.  
 
That seemed hot so I googled it and found some mixed messaging.  Mining forums generally say anything above 80°C is no good and will severely impact the lifespan of the card, and could outright fry some of them depending how hot you get (this was in reference to ALL cards, not specifically this one).  Other forums specifically talking about 2080ti cards said that anything under 90°C is fine, BUT these forums tended to be talking about video gaming so I was worried they might be referring to a limited time at that temp (while playing) vs mining which would be 24/7 (while not gaming in my case).  
 
Can anyone clear up that question?  Is 85-86°C too hot to run this thing at constantly?  As I'm waiting for parts to arrive for my new build I had put the card in my old build, so it will end up with better air circulation in it's final home - but I want to gauge what to expect or aim for on this thing.  Definitely don't want to break it given the cost.  
 
Model is 11G-P4-2380-RX, VGA,2080Ti,REF,BLOWER,11G,TypeC+HDMI+2DP
 
Thanks! 

For mining, for maximum profitability, you will want to underclock the GPU. Look at your hash rate versus energy consumption. Underclock the core, overclock the memory.
Once you maximize the profitability, you should also see that your temperature concerns have subsided.

So as an update:  I started toying around with MSI Afterburner and underclocking the core last night.  I was able to crank 1750mhz at 825mV and that dropped the temp to the mid/high 70's without any additional fans.  I already have the side off the tower so I additionally added a desktop fan pointed directly at the GPU and that got it down to a constant 72°C - so for the time being I've got it running at that.  I'm going to get into the overclocking the memory portion tonight (too many responsibilities to do it all last night - friggin offspring) to see if I can improve the performance at all (underclocking the core lost me about 5-7MH, down to 44-47 from low to mid 50's before).  
 
I think I'm going to solve a lot of my problems once I get the new rig assembled as it will have significantly improved airflow and 3x the fans.  Although now I'm trying to figure out the viability of cramming every card I own in there to maximize my mining, so we'll see how this goes lol.