Is there any way possible to have a widget like the Upcoming Cards but have it be for 1 specific list/column in Deck, and show just those cards? i.e. so a few widgets to monitor specific lists could be added to the dashboard.
In the Web UI? I don’t believe so.
On mobile I know it’s possible with the Android Deck app as that’s how I use it. 
For the web interface, you may want to see if any existing issues are relevant.
If so, add your vote 
so that the developers know how to prioritize development.
Another option would be to make an attempt at implementing it yourself or collaborating with someone already doing work in the area.