Best way for insulating double-door?

[OliviaMumsnet]

I know that some clever MNer will be able to help with this one.

I've got an external double- door which is about 1.5 x width of a normal door.

Both doors need to open to use the door.

There is no more "wall" outside the frame to use a recess for curtains.

What's best plan for keeping draughts out?
TIA

any good?
www.jim-lawrence.co.uk/curtain-poles/portieres/33
www.thepolescompany.co.uk/blog/?p=33

I'm assuming that the doors are hardwood as upvc shouldn't be draughty. As such you can tack on some flat beading that overlaps both doors and use some self adhesive draught excluding as an extra cushion as it were. Remember to check which way doors open before tacking beading on! Ofc if they are upvc there's something wrong.