Consume power usage clarification
No.

You are reading too much into this rule. “Fully used if possible” can also be understood as “used as much as possible”.

Now, let's assume your interpretation is the correct one. Using the boardstate you described minus the New Vinland. You could consume only one good (or even 0 by arguing that it is not more than 3), which is against the spirit of the rules (you must consume as much as possible).

So, while I do not have an authorative source, I can say that your interpretation is not the intended one.