Plan upgrade for specific meeting

[Kittastrophy]

I currently have the Pro Plan which allows for up to 100 participants. It is renewed on the 22nd of each month.

I have a large meeting coming up on December 2nd which will most likely exceed 100 participants so I would like to buy the Large Meeting Plan for one month. If I bought up now for the 1 month of the Large Meeting Plan does that cover December 2nd? There was some language about prorating this month and then being charged again on my regular renewal date so it sounds like I would be paying for Large Meeting Plan for two months instead of just the month of December when I need it.

Also, I need to create the meeting and send out the Zoom link now. If I wait to purchase the Large Meeting Plan after the meeting is created in Zoom does that affect the meeting link or any aspect of the meeting? Or does it just automatically allow any meeting created before the plan upgrade to seamless transfer to the new upgrade options?

Thank you for your help.

Kitty