Thanks all, I ended up just getting the 5500M 4GB GPU. I figure if I need more, an eGPU is an option. I suppose now with TB3, eGPU is an option that was not available before.
Hard to believe for me that when the 16" MBP came out, I thought I'd be getting 2.3 i9/64GB RAM/8GB 5500M/4TB SSD for north of $4500. Now with all this deliberation, I end up getting 2.3 i9/32GB RAM/4GB 5500M/1TB SSD refurbished for less than $3000.
I guess it pays to go through my Photos library and really dig through what needs to and what does not need to be there. Cleared out about 60% of my photo library. Those 36MP DSLR burst shots sure add up!!!