I would try selling it to 10 customers (without changing your pitch) and if you don't get 3 customers to buy, then adjust.
It's less about time and more about # of learnings. I don't like interviews, I like asking if they have the problem, showing them our solution (verbally or with a visual) and then asking for their business and taking their money.
If they don't pay, doesn't count.
Don't spend it, test the complete group (or 10 min) and then decide to pivot, or preservere.