I’d offer a different perspective on availability during holidays such as Easter for business class awards. My experience has been that there are very few paid business travelers during these periods and it can be prime time for getting multiple saver level awards. I have gotten five awards for my family during Easter Christmas and peak summer vacation time in August over the last few years.
I’di check all the gateways and grab the best thing you can find. I agree that Iberia can be a decent bet if you grab the seats before they are gone and consider purchasing a domestic connection if need be to get to their gate way.