Sweet image! I have it as a fav myself...

but yes too long for render....as an FX pro this is far to long and the main reason why TG has failed in the fx community....

We would either matte paint it.....or do model of it in renderman or mental ray....which would slice trhough that...(or paint on top of that)

keep to landscapes TG! And its also the whole matte painting team from ILM endorses V6

the average matte is 70-140 hours (for something like that) 1-2 weeks