Do I Need to Apply for a New Non-B Visa Before My Current Visa Expires if I Am Outside Thailand?

My visa ends up next week but I’m still out of Thailand. But my work permit is still valid until next year (extended last March). Do I need to apply for a new non-B before my visa expires or I can apply later e.g. a few weeks before flights to Thailand resume? Will my work permit become invalid when my visa expires or are these 2 documents independent of each other? Thanks!