The current patch version of our SharePoint Servers are Nov 2017. What is the safe CU we can go with?
If we have to go with Jan 2020 CU, can directly hop from 2017 CU to Jan 2020 CU?
Yes you can Hop directly to Jan 2020.
I am not seeing any issue in CU last year or so. I think Jan 2020 is good choice. But please remember, you have to go the lower / test farm 1st to check it completely.
I would suggest you install the latest patch Feb 2020 CU. The lastest CU contains all the update before.
Yes, of course. You can directly hop from 2017 CU to Jan 2020 CU.