You really need to upgrade that card. Something more like a 20 series, with at least 8GB VRAM.
There’s no point in baking the scene and then using Lumen for reflections. Lumen is not very good at reflections, but is good at scene lighting. So you might need that the other way around 
You can use UE5 and turn Lumen off, and carry on with static lighting, that way, you get some new stuff, but don’t have the performance hit. Having said that, even without Lumen, UE5 will drive your GPU into the ground before you really get started.
If you are going to use 5, then 5.4.1 is noticeably more performant than the other versions so far, in my opinion.