Allow portal invites to last for longer than 24 hours

I would like the ability to have the registration links people invited to join private idea portals to be active for longer than 24 hours before self-destructing. Some people don't check their email that often, read it that carefully initially, or might be on vacation and not able to respond.

Also, if they reply back to the email it won't come to our team nor can we customize the message letting them know who to contact if the email invite does expire.

Are you able to share the reasons behind having the link expire after 24 hours?