Iberia Airlines has availabilities for their lie-flat business class, including summer of 2023, for 50k miles. However, for the best availabilities for 2 passengers would be from October to November of 2023. You can book this seat from British Airways Avios miles on their website. The US cities include Boston, Chicago, New York, D.C., Miami and Dallas.
The direct flight is with Iberia Airlines, and they might be going fast. However, there are still connection options with British Airways. However, you will be paying a whopping $900+ for the tax and fuel surcharge, not really worth it in my opinion.