You're going to struggle going long haul on BA with 86k Avios. NY is £160k return and that's one of the shorter long haul sectors.

You might have more luck using it on Iberia as they charge far fewer Avios and the companion voucher is valid.

Fees are also considerably lower but you must book exMAD and you'd need to factor in the cost of positioning flights to/from MAD.

January 2024 is very soon so there may not be any availability, but South America in business class on off peak days is just 51k one way to somewhere like Buenos Aires so you could do PE out, business back.

Good luck.