Can you dye them different colors?

You probably can ,but we haven't try, so try to dye em with your own risk

Do these hold well? Wanting to order for groom and groomsmen for a wedding, but dont want to settle for cheap price if they wont hold well

My son used these for my sisters wedding and he was being the typical boy (jumping around, dancing, sliding on the dance floor, etc.) and they help up to that!

Is the bow tie adjustable to be able to fit a 19in neck?

Oh so close, when measuring (cloth portion and the two metal buckle ends (that interlock together)), you're at 18.5 in.

Are these made in the US? And will shipping be affected by corona virus?

No, they are not made in the US . We believe the shipping will not affect by the coronavirus. Amazon fulfills our customer's shipping and handling, in this case, it’s best to contact Amazon’s Customer service for the most up to date shipping information. Let us know if you have any other questions. Thank you Trilece Cutomer Service Team