How much Genetic Engineering is required...

[blue emu (OP)]

... to create a Human sub-species that can live on Titan with zero Infrastructure... assuming that we Terraform it to the maximum of 3.0 Greenhouse?

[Nathan_]

It is possible to get titan up to ~-42C so basically -20C, maybe 1 temp ring increase as well. 40k-50k research total probably.

I've been trying to set up a game where genetic modification would be worthwhile, but small games and invaders don't go well together.

[blue emu (OP)]

It is possible to get titan up to ~-42C so basically -20C, maybe 1 temp ring increase as well.

Cool... so I'm about halfway there.

[Marthnn]

Titan has a base temperature of -196. 4°C, which is 76. 6K.  With its albedo of 1. 00, fixed by not having hydrosphere, you can get at most a surface temperature 3X the base temperature (in K), which is 229. 8K or -43. 2°C.   

Considering the default human species having a base temperature of 22°C with a range of +-22°C, you would need either "Base Temp -40C" and "Temp Range +4" (to get to -18°C +-26°C) or simply "Base Temp -50" (to get to -28°C +-22°C).  That brings the total research cost to 155k and 160k RP, respectively.  Edit : Plus designing the new species itself, which can be several thousand RPs.

Unless there's something I don't really get in new species (never done it myself).   

[Nathan_]

You're right, I thought that -20C meant -20C not species mid - 20.