Looks like this when hit:

can you try how it looks with the component InlineMessage from Kirigami?

In what circumstance is it enabled? If it's only enabled when the weather forecast is disabled, perhaps we should instead use ratio buttons, like so:

Compact mode: (0) Show weather forecast
              ( ) show temperature

Not related to this patch of course, but your screenshot reminds me: we should move the labels to the right of the checkboxes to be in line with the KDE HIG: https://hig.kde.org/components/checkbox.html

Meh, forgot about ensuring proper wordwrapping, but somehow

Layout.fillWidth: true
wrapMode: Text.WordWrap

don't have the desired effect, seems the groupbox is messing into that.
Screws this approach.

In D12944#264142, @mart wrote:

can you try how it looks with the component InlineMessage from Kirigami?

Somehow InlineMessage does not play well with GridLayout :/ And then same wordwrap issue. Meh config pages and minimum width behaviour...

In D12944#264144, @ngraham wrote:

In what circumstance is it enabled? If it's only enabled when the weather forecast is disabled, perhaps we should instead use ratio buttons, like so:

Compact mode: (0) Show weather forecast
              ( ) show temperature

What the info was trying to tell: showing in compact mode additionally the temperature is only available if used in a location where there are no size constraints.

Seems this is not that quick & easy to solve, and given I have to run now, no chance to do this last minute dirty improvement for 5.13, People will survice this :)
Will pick up later once I have landed some more changes which then again would influence this config page (which is the reason why I had forgotten about that issue, hope was to get those features done for 5.13).

Thanks for quick reaction for now.

No problem, take your time!

Looking like this when triggered:

Message text might need more improvement, proposals welcome. And fine to do master-only, just completing things now this has been started to deal with.

+1 for redoing the checkboxes to follow the HIG! There seems to be a bit too much padding between them, though.

As for the message, how about "Temperature cannot be shown because this widget is a part of the system tray, so there would not be enough room."

However, a nicer UI might be a way to actually show the temperature when it's a tray widget instead of the current image. Something like this:

Display today's: (o) Weather condition image
                 ( ) High temperature
                 ( ) Low temperature
                 ( ) Current temperature

That way there would actually be some options for people using the tray widget, instead of a disabled option sitting there taunting them that we have to explain or else we get bug reports.