Yeah, sure. Now, the result of course depends on a lot of things; how fast lens you use, light conditions, how good you are at handholding on a bit longer exposures etc.
Originally Posted by marciofs
If you are using Tri-X (probably works the same way with other similar films too), the development time for shooting at 400 and 800 is the same, so you can push one stop even if you shoot the same film at 400 during the day.
Also, with most cameras it is possible to change films in the middle of the roll. Just make sure you don't rewind it all the way in to the cartridge (this may take some practice on some cameras). Mark the roll with the number of exposures. When changing back, just shoot the amount of exposures taken with the lens cap on, and you are back where you started. This way you can use one body but different films for daytime / night time.