Is it possible to create, then save an open ticket on a stand or register (iPad), then close the ticket and charge the customer's credit card using the Square Terminal?

Our situation:   We like to create tickets, save all of the items that our customers are purchasing to the tickets, then close them out when we are done.  But, we would like to carry the smaller Square Terminal to their table to close out their ticket and take their payment.  We've been lugging around the iPad and square readers.

IF both devices (iPad & terminal) are on the same wifi, logged into the same store location/account, can this be done?  I've read conflicting answers in the community.

Thank you.

If I open a ticket and add a bottle of wine, then customer comes back and gets another bottle, I know I can add that second bottle. When they come in to check out, they want to take home another bottle. We discount the bottles when someone buys 3 or more. I can't seem to update the item price to choose the 10% discount. I have to void the item and add it back, which is very time consuming and not very helpful. Am I missing something?