Should I use a plug-to-plug adapter to connect extension cords?

No — plug-to-plug adapters (male-to-male or female-to-female) are dangerous and often illegal because they create exposed live prongs and risk arcing or fire. Instead, join cords with a proper male-female connection or buy a single long cord rated for the distance and amperage. Voltage drop depends on total wire resistance, not the connection method, so prioritize safety first.