You may go to your gate ''approx.'' 50 minutes before your flight and ask the gate ground service to block your seat next to yours or request a change of seat to an empty seat next to you, at the same time blocking it to ensure you can have an empty seat. I think that will be the best choice.
PS! Wouldn't mind guesting you into the lounge, but wont be flying on the 1st. Sorry!
Sincerely,
SB