There is something I read online once about how to un-shrink your clothes (I had a Disney onesie that was really comfy and shrunk in the wash, didn't even tumble dry it, was just washed at 40 like it said

)
I'm sure the link said about soaking the clothing in baby shampoo and you keep stretching it out and soaking it. I never got around to trying it yet but might be worth a Google
As for sticking clothes on an airer, I don't have a garden so I have no choice but to dry inside. I always make sure I have a window open and have the airer by the radiator in winter. I also stick one of those absorber 360 things underneath it when the weather is really cold, just to absorb some of the moisture from the air
(You can also buy heated airers but I don't know if they're any good)