The upload limit is set, and there is no way to change it, both temporarily and permanently.
If you follow our migration guide, you should have no problems with this:
Migration features integrated in website software (i.e. migration plugins) may seem like an easier solution, but in our experience they rarely work as well as advertised, and you’ll just spend a lot of time fighting with upload limits, time limits and so on.
Our guide is a little bit more involved, but works reliably for all websites of any size.