low power consumption

Hi again!

I'm working in a PIC16f876 with some ICs (manchester encoder,epprom,etc...) and they're battery operated so I need a low power consumption cost efficient.
All the rest of components have the power through voltage regulators (LP2950) because they have others voltages (3.3V, 2.5V).
I've an idea:

Put the PIC in sleep mode, and use a solid state relay to put its contact opened to voltage regulators grounds so then I will have only PIC sleep mode power consumption. Using a interval time (15 minutes) the PIC wake up and close solid state relay contact and wait to all ICs start up. Then runs a few lines of code (using ICs) and after open RSS contact and disconnect all components but PIC, obviously, and enter in sleep mode again.

can I use only ONE RSS with all the ICs grounds connected (respecting current Amp.)?
has anyone tried this before?
has anyone a example of picbasic code for this?

Regards.