I don't have the time nor budget to shoot this film.
...than you can absolutely not do a feature length CGI film.
CGI takes a lot of time. Justin and Ryan are two very experience artists with mostly all of their own tools. It took each one of them roughly 17 hours to create model animate and render the ghosts.
...and a lot of money,
In addition to the amount of time, there was something to the tune of 3TB of data used in the creation of the creatures and 1.5TB of data just for the film, which includes a made up amount of 6 backups.
1TB(internal) = about $300-$400. Two years ago add about $200 to that number.
then add monitors, software, RAM, hot pockets, french masseuse and an ergonomic chair