We are currently trying to do the same thing, meaning to deploy from Dev to Qa/Prod the queries and dashboards.

For queries it is possible, We tested this in a python script and the queries were successfully recreated in the new environment . I am not sure how to fix the links to the data sources yet.

For the dashboards, it does not work as the widgets are ignored/not parsed when I tried to call the API to create a dashboard. Just an empty dashboard is created. I even tried a simple dashboards with a single text widget and it still didn't work. Maybe it will after this gets out of the preview.