fionas i used a supply line with DS1 for a little while i haven't read the resent pages but is it EBM you're useing? if you can guessume your DD is going to wake at say 1:30am pull out the EBM and pop it in the dispencer thingy (cant think of the name right now) and pop it between your boobs about half hour before and tape the line along your boob to the nipple ect. this a) warms the milk up to body temp and b) is ready for the feed before hand. i found this worked with DS1 as the milk comming from the breast was the same temp and all as the supply line.
you're doing a good job, i admire you for trying