How to tell company-jedi / jedi-core / python-environment to use a Tramp virtualenv?

[jennykwan]

I probably don't understand virtualenv implementation well enough, but I simply don't grok python-environment well enough to figure out how to use dir-locals.el on a remote Tramp-accessible-over-SSH server to tell local Emacs running company-jedi to load a particular remote virtualenv for this project (using Projectile and Helm).

(I'm on a consulting engagement with a large Silicon Valley tech centered company that is very constraining. Remote servers are required for development; I cannot check out code locally. These boxen don't get network access to PyPi. I'm doing data engineering and their Airflow-equivalent is indirected away so the Python codebase I'm interacting with is deployed into the Airflow-equivalent source tree so I had to reverse engineer their build process to get the Airflow-equivalent Python code and its dependencies loaded into a remote virtualenv. This is the last yak I want to shave, but the lack of autocomplete is killing me. /vent)

So:

1. What vars do I need to customize to use a virtualenv?
2. Will this work with Tramp if both the base Python and the virtualenv are both remote?
3. Would a remote .dir-locals.el at the project root work? I.e. does the Jedi-containing Python load late enough such that I can customize at the project root level, and have Tramp fetches respect that?

I'm more than happy to help write docs.