Only 2 fans sucking in & 1 fan out might be a bit to little of airflow ? you can make sure it is not the card by taking off your side panel for freeflow air & retest your temps .
What case are you using ?
What are the rest of the system specs of parts in side the case ?
Could be you trapped the Heat in the Case as that cooler pushes most of the GPU heat into the case --> Your case fans need to remove the heat
Now - if 55 C is your idle temp after the PC sits overnight - that would indicate a possible issue with the TIM application - not covering the entire GPU Die
Please remember: If you cause physical Damage to the card while changing the TIM - that would Void your Warranty. If your experienced & comfortable changing the TIM - you probably think it is reasonably easy to do.
If you RMA a New Card - you would get another New card - though you have to pay shipping & wait for the replacement EVGA Warranty
(excerpt) If an RMA is necessary within 30 days of the original purchase date of a new in box Product, a new in box OEM replacement will be sent to the Original Purchaser in return, subject to availability. How To RMA