When to Disable and Recreate Indexes in Data Warehouse ETL?
The answer depends on a number of factors:


What is your goal:  Minimal I/O?  Minimal time to load?  Minimal effort to set up?  24/7 query performance?
How heavy are the indexes: Just one index with on ID column won't make much difference, but several indexes with lots of columns will make a significant difference.
What is the bottleneck?  If the data load is coming across the network, writing to disk may not be the bottleneck if you're writing to a high-performance SSD subsystem.  If you can write the tables and indexes as fast as it comes across the wire, then there's no way you'll make is faster.


So determine what your goal is, and then test each method.  For a 5 GB load, it should be a quick test.

Having said all that, for a 5 GB load I wouldn't bother trying to optimize it.  SQL Server can write that in just a few seconds.  Pick a strategy and run it--if it takes two minutes, then you can only make it about 2 minutes faster--is it worth your time?  If you're approaching this as a learning exercise, do it with a significant amount of data--something that will take 30 minutes.