Multiple hotplates would work. Split the wort in half. Once they are both boiling, mix them together in one pot.
If you are just starting out and doing extract (with maybe some steeping grains), you could get by with a partial wort boil as well. Boil two and a half gallons (including the extract), and then after an hour, add the rest of the water that has been in the fridge. It will cool your wort right down to pitching temp.
I strained my hot wort into the fermenter, added a few gallons of cold water, and viola, was just about ready for the yeast.
Maybe someone else will have some better ideas... which is quite possible... lol
Welcome to the forum....