And LOTS of seasoned firewood to boil it down.
Yes and no.
You do NOT want a roaring fire under your sap. That will caramelize the sugars. You need it hot enough to evaporate but not to boil. There are things you can do to increase heat efficiency like building baffles around your fire or bed of coles/embers to contain heat under your evaporator leaving just enough gaps to allow some oxygen in to feed it. Once you have a hot bed established, since you don’t want a raging fire, you can simply give it occasional cut branches. You don’t need seasoned logs.
That is why I said it really just takes patience.