I think it’s great you are going forward and not getting discouraged.
I’ll be interested to hear how your strategy goes with developing the websites in advance. Obviously could have some scale issues but if it gets you over your “no portfolio” issue then you could abandoned it when that is no longer a concern.
How many of the 100 that you called had this concern about a portfolio?
The reason I ask is because it is difficult to know if it is your product or your pitch that is bad. Your pitch can be improved (ie portfolio, better highlighting benefits to the customer), but if you don’t have product-market fit you need to move on.