Hi Leeroydan,
I guess it depends which base you make and how long you let it simmer for. If I am making Taz's, JB's or CA's base, I can get as many as 6 or 7 containers from a single pan (sometimes this is not quite enough when I come to make a serves-2 Jalfrezi or is a little too much if I make a serves-2 Chicken Tikka Masala or Madras). Four days ago I made a Balti base with more water than in the recipe so I don't burn out my blender. After letting it cool overnight, I blended it several times the following day and yesterday I simmered on a low heat for about 3 hours to reduce it back down. When I got home late last night and could still smell it, I couldn't resist making a quick chicken balti. Today I intend to make some more chicken and some meat Balti dishes and any left over base will be frozen in about the same quantity as I save for other bases. I only expect to have a couple of portions left for the freezer.
I guess the answer is really, "save as much or as little as you intend to cook with". I always tend to make curries in portions of 2/3 servings at a time but if you are only intending to make enough for 1, then portion it out so it is just enough base for each and as Mickyp says, make sure you have enough freezer space.
I hope that helps.
BAJ