A lot of that is going to depend on what size output you are looking for. You might look at the "Export as Multiple Files" feature and, depending on how big you want things to be, only export it at two or three levels (jpeg files with html). With that, you'd only have somewhere in the area of 4 to 16 files to paste together. Another option would be to export it as a spherical map (not really a sphere, but can be evaluated as a sphere by other programs).
In a nutshell, though, here are the steps,
File > Export > Multiple Files
When the dialogue box opens,
- Click the check box for Generate Jpeg files
- Click the check box for Generate html files
- Chose how many map levels you want to work with
- Select a directory to save the files to
- For each map level, define the number of files high and wide you want to generate, the overlap (I tend to use 0) and the resolution. Note, however, that the greater number of Map levels and/or resolution, the more the images are going to degrade.
-Once satisfied with the settings, click on OK and FT will do it's thing.
Finally, stitching the files together is pretty straight forward, though you may have to deal with a bit of "beveling" that sometimes shows up along the edges of each file. This might be solvable by adding in a little overlap in the Export Settings dialogue box before you start the actual export.