Welcome to FT!

Yours is a bit of an ask; multiple business class seats are always tricky, and the current huge reduction is service is giving airlines a big headache in advance planning. I’d wait and just keep trying, something may come up closer to the date. It might not though, since with reduced demand and supply airlines may just focus on selling seats. Depending on your citizenship etc, and the likely extension of restrictions, you may not be permitted to enter Spain.