I have tested it as low as 80px and the scrolling marquee was always within the module's width.
The module's width cannot not be lower than the weather icon width (80 px) or the width of the station description being displayed (whatever comes first). So if you need to be economical with space, use short station descriptions.
I believe the MambWeather problem is related to the positioning/alignment of the left column of your website, possibly by the stylesheet (CSS).
The weather icon, station name, temperature, marquee and details list are all well centered vs eachother, but NOT centered vs the module container, i.e. the box with the round corners.
Maybe you can try the following:
- Go to the MambWeather module settings (backend).
- Module Parameters / Module Class Suffix: enter “_mambweather” (without the quotes). This overrides the standard template.
- Save the parameters.
Then see what happens on the frontend website