It Depends. Setting up robust LODs is going to be critical your performance. Creative optimizations will be necessary to make it run well for you. Baking light maps are likely the most challenging thing on your hardware, your memory is your weakest link when it comes to baking.
It is totally possible to get something like GTA V on your PC’s hardware, they did manage to get GTA V to run on a console with only 512mb of RAM for both graphics and data.