What is the best / quickest way to get from Pop Century Resort to Magic Kingdom for rope drop?

Take a bus over. Or do what I did have breakfast at Grand Floridian Cafe and get over to Magic Kingdom by boat monorail or even walk. The buses do start at a certain time before the parks open. Ask guests services. I hope that helps.

Take the bus. Do your best to leave 40 to 45 minutes early.

Buses always.

Buses start an hour before parks open.

Use the bus it's the easiest way

Definitely the bus.

Bus. Be in line when they first start picking up for the park.

Best way is to take a bus.

Fyi you probably want to arrive at MK at least 40min before rope drop time