Dell G7 15 Experiencing severe gaming performance and possible temp issues

Hi, so I have a Dell G7 15. Purchased last June. It uses the i7-8750H CPU, Nvidia 1060 with Max-Q design GPU, and 8GB of RAM. When I first got it, everything was perfect. I played games on it pretty often with multiple hours per session at 60fps. About 10 months in now and I've noticed games begin to stutter, so I installed some monitoring tools. I found that some time after starting up a game, usually 5-10 minutes in, the GPU would reach a temperature between 76-78 degrees and it would remain there throughout. Also, the GPU would reach a utilization of 100% at which point the game's framerate would significantly reduced to around 15fps, will sometimes jump back up to mid 40's-60's for about two minutes, then back down. When the GPU is at 99% the framerate reduces to 30fps. Doesn't matter what game I play or how low I set the settings, once the temperature reaches 78 degrees I know I'll be experiencing severe framerate drops from there on out. Am I still under warranty to send it back in? Is there anything I can do or others that have this problem? Noticed this same GPU with a similar model laptop was posted in April 2018 with the same issues. Any help will be appreciated. Thanks.