That's what sprang to my mind,too - just halve the cream cheese. Or have half cream cheese, half something less rich - maybe cottage cheese instead (put it through the blender so you don't have that "lump" thing going.)
If you do decide to just go with less cheese, fill up the space with veggies - peppers, either hot or sweet, or corn, maybe a bit of diced tomato. If he doesn't like refried beans, maybe just open a can of kidney or pinto beans, or black beans. When they are whole, they don't have that "mush" quality of refried, and are also a lot easier for people who don't like them to just pick them out.