Hide Incoming Variants or Merge Products?

[HANDHHER]

We have a number of products which we sell year-round, however we add new variants. I have to add the new variant to the Product to create a purchase order, but then the new variant shows on our online store.

1) Is there a way to hide variants from online store?

2) If not, is there a way to merge products once new variants on POs are received?

Thank you!