Export map to specified size?

[mrus...@g.rwu.edu]

Good morning, 

I am using the Georefrencer tool online to add data to a raster. I have successfully added data and been able to export the working raster. I am using a program that requires a raster with the size 2048, 2048...after exporting my working raster, the size was 5645, 6211. Is there a way to export the file to fit 2048, 2048 without losing any information. I don't want to crop the map because the information is relevant to the project. Is there any other solution?