Assuming grub (not grub2) almost everything needed by grub is in the /boot/grub directory, which I assume is on sda5.
As long as the identities of the partitions don't change, all of the contents of /boot/grub remain valid across changes in the sizes and starting points of the partitions.
Part of grub is executed before the part in /boot/grub. I'm not sure myself what changes in partitions are possible without breaking that part of grub.
There is a simple command that can be used to reinstall that initial stage of grub (and reconnect it to the part in /boot/grub). I always forget where to look up that command, but I usually take the trouble to find it before changing partition sizes and I make sure the bootable CD I'm using supports it. Then I usually discover I don't need it, grub is still correctly connected after resizing partitions.
and I have to reconfigure the lappy's 2 OS's from scratch.
No, you don't. You just need a bootable USB or CD Linux and you need to use a simple to type (maybe hard to find) command to reconnect the MBR to the correct /boot/grub directory contents.
If you change the identities of the partitions, things are a bit trickier, but the /boot/grub/menu.lst file has pretty simple contents, so it still can be easy to fix. If you deleted the Dell utility partition then the Windows C: drive would change from sda2 to sda1, requiring a tiny change in /boot/grub/menu.lst. Conveniently, your Linux partitions would remain sda5 and sda6 even if you delete any or all of sda1 through sda3. If the identity of the linux partition changes, I think you need to make edits to /boot/grub/menu.lst plus edits to /etc/fstab and I wouldn't bet there aren't some other edits needed that I'm forgetting.