Probably need to start thinking about it seriously once again.
One needs to have a huge memory card if directly doing it through the camera intervalometer.
The better way is to do it through a laptop connected via the software for controlling the clicks (ideally that would be the EOS utility provided by Canon). This way, the images get directly stored in the hard disk of laptop hence not much worry about the disk capacity. However one needs to see the battery backup of the laptop as well as the camera. Since time lapse takes a lot of time, hence it is apparent that one of the batteries will surely go off soon. Try AC adapter for both the laptop and camera, for long durations.
The Melting of the Ice Cubes through Time Lapse Photography
The burning of the incense stick through time lapse photography
The Hyderabad dusk setting-in through time lapse photography