I can't find anything that says the newspaper comic strip business is affected by the crisis.
The regular comic industry is affected due to comic stores closing and the main distributor has halted deliveries.
In contrast, many newspapers and news sites are still operating, and most convenience stores, which sell newspapers, are deemed essential and are still open.
So, one can correctly assume that newspaper cartoonists are working from home, like the other news reporters.
Also, I looked through today's comic strips. Some are reruns, others have social distancing and being quarantine as topics, and the rest is business as usual.