Yes, using load on demand should help you quite a bit. It will mean that, when you load your data, Tecplot only needs to load the first time step, rather than all 500 time steps (assuming you create the zones with the correct standIDs and solution times). Another thing that can help a lot is if you share data for the spatial variables among zones if the mesh does not change over time.
But keep in mind that even with a single variable (i.e. x, y, z, and one other) a single time step of data is still over 3 GB of data (if I did my math correctly). So it may never be possible to load the data on a 2 GB machine, unless you introduce the ability to skip some of the data (like IJK skipping, or something else).