Question GPU upgrade for an ASUS G20CB gaming PC ?

[archaicguy]

Looking to upgrade my GPU.
My current system is a prebuilt ASUS G20CB gaming PC with:
I7-6700
16 mb ram
GTX 970 is the current card that I want to upgrade

Due to the size restrictions etc the best video card I think I can upgrade to is a GTX 1070 TI.
Would it be possible to install the components in a larger case and then be able to run a larger card like a 2080 TI or is the motherboard also a restriction?

 

[Fix_that_Glitch]

The RTX 2060 would be a good match for your cpu. And it is a smaller card than the 1070ti and cheaper. As long as your psu is about 550w or greater.