What to use?

[Strawberry2017]

We are hopefully moving house in the coming weeks and I was planning to take our vented tumble dryer with us, however I have no clue what to do about the hole in the wall that will just be left?
It's covered on the outside by a vent cover but I would need to do something to fill it on the inside so it doesn't let cold air in.
Can anyone advise the cheapest easiest way to cover this?

Just to block the draught some news paper in a plastic bag stuffed inside. If you want a nice job you'd mortar a brick to size on each side potentially with insulation between, and then plaster and paint inside

Looks like they do tumble dryer vent blanking plate but they aren't cheap. What about a piece of cardboard fixed on with tape.

Insulation and blanking plate is what we did

put a hit and miss vent on the inside. Four screws. It can be opened for ventilation, or shut for not, and looks neat.

£2.39.

www.screwfix.com/p/map-vent-adjustable-vent-white-229-x-152mm/7374d

Fill it with rock wool insulation then put a bit of plasterboard in the hole near the wall level and use easy-fill plaster to fill the gaps and paint over.

Do the people buying your house have a tumble dryer? Surely they will just plug theirs in where yours was?

Piglets suggestion is probably easier

Thank you everyone I really appreciate you taking the time to help.
I'll see if she had her own tumble dryer and then go from there.

Personally I wouldn’t do anything to block the hole up. They may want to put their own vented tumble dryer in once they’ve seen the hole there; or they may have their own way they want to block it up.