HI there I want a blind for my kitchen back door to keep the heat in better in the winter. to cover the door it needs to be 81cm x 30.5cm I think a simple roll up blind would be best for this? (one that is very easy to fix in place would be best with a minumum of drilling, screwing etc) THe one complicaiton is that we need to have a slot taken out of the bottom of the blind 40cm x 20cm to allow access to a cat flap when it is down. Do you supply a blind that would allow us to cut out this slot and the blind still works ok? Or do you have another sdolution? Very grateful for your help with this, thank you