Jokes aside, the limiting factor will be either a technique to pack all of the code into smaller tokens like semantic search (someone else will be able to comment on this as that's the limit of my understanding) or GPU memory for input tokens.
Buying a "high end GPU" isn't buying a 4090 or even two, it's 250k on a DGX unit and putting it in a datacentre. You will probably be able to find a service that would sign a confidentiality agreement and provide you with this service for less than 250k.