There will be a grain and contrast increase, as well as a color bias shift towards the red/orange range. I would first take a light meter reading of whatever subject matter was lit by the lighting and see what Exposure Index [ISO equivalent] range it falls into. For example, if there was a person in the scene, put someone in that spot, meter the light falling on the subject with a hand held light meter or 35mm SLR or DSLR and see what exposure range you have at ISO 200, ISO 400 or ISO 800. Anything in the scene that falls below the threshold of the film's ability to record it in low light, will not have anything anyway. By pushing film you are increasing whatever is actually being recorded on the film to bring the image density to a more desirable range. Once you have determined this, you can then go ahead and push process the film, either 1 Stop, 1.5 Stops,2 Stops or even 3 Stops if necessary. [Note: a 3 stop push would be extremely dramatic and needs some careful consideration, but up to 2 Stops should be fine]. I have often pushed the now discontinued EKTACHROME films similiarly and gotten good results, with the caveat of the grain and contrast increase, and under tungsten lighting a very warm color bias. For what I was working on, I was pleased versus having a very dark unusable image. If you doing your own processing, I always recommend shooting a few feet of the scene that you might want to push, and then remove that strip and process it and evaluate it to see if the push is necessary. You could do that from the end of your film, but you'd have to sacrifice a second or two of runtime of your film for that purpose. Only you can determine if it's worth it to you. Good luck!