Your energy reduction is brilliant already!. If you say you've checked and there's definitely a foot of lagging in the loft I will never mention it again EVER. I'm sure someone in our family had a £600 winter quarter one year, the mind boggles.
I used to use loo roll to block gaps in our last house.
Ipsos, the drill bit you need can be hired cheaply, then you'd need a plastic vent cover for the end of the hose. My ndn has hole in her wall for the dryer. It's a very neat way to do it.
Nice, my dh complains he's cold and all he's wearing is pants and socks. Anyone would be cold.