Fix Premiere Pro lagging by connecting onto an external monitor?

Hi community, 

My premiere pro is lagging really bad, and I know it's the problem of the graphics of the monitor because it would start lagging when it's overheating/when I watch shows for too long...please see below  the setting of the laptop

I think the setting for the laptop is pretty solid as it was one on the higher ends when I got it in 2019, so I want to ask, can the situation be elevated if I buy an external monitor? 

Any pointers are really appreciated! Thank you!