PIC power consumption with internal rc

I was planning on using a PIC 12cxx microcontroller for an application where low power consumption is very important.

Timing isn't critical so i was planning on using the internal 4 Mhz clk.

From the datasheet it says that current consumption is about 1mA at 4 Mhz.

So i'm wondering if i used an external xtal if that would greatly reduce power consumption into the uA range.

Also, i believe there is some type of prescaler for the clock. If i used it to bring the operating frequency down to 32kHz would that decrease power consumption.

Basically i'm trying to find out what is the best oscillator to use to minimize power consumption when timing isn't critical and an operating frequency of 32k is plenty fast.

Thanks in advance

Thanks