[Development] Maintenance Tool with offline install function?

[André Hartmann]

Hi all,

Yesterday I installed a Qt 5.9 beta snapshot and I'm impressed how much 
the Maintenance Tool improved! The possibility to install Qt versions in 
parallel and to remove single components is awesome!

There is one thing missing to make it perfect: Allow to store the 
downloaded archives local and install from that location later (The 
Cygwin setup allows this in a similar matter).

This will surely help all the companies where computers have on internet 
access at all. So far I have always downloaded the offline installers 
(Windows mostly), but thats a pain if you need them in parallel or want 
to update Qt Creator at a time (I don't remember how often I have set up 
Qt versions and Kits in Creator).

There is already a bugreport for this: 
https://bugreports.qt.io/browse/QTIFW-573 but there is no progress since 
two years.

Thanks, and best regards,
André