There would not be a lot of rebloomers that rebloom in Zone 5a. From Sutton's
https://www.suttoniris.com list of iris that should bloom in Zone 5 and above.
Autumn Circus
Autumn Rain
Bolder Boulder
Double Shot
Golden Immortal
Lord of Rings
Masterwork
Raspberry Frost
Summer Waltz
Sunset Punch
Others I know of available at Winterberry Gardens
http://www.winterberryirises.c...
These are often mentioned as reliable
Daughter of Stars
Feed Back
Immortality
Rosalie Figg
I am just starting to get into rebloomers, There are a lot of smaller iris that rebloom as well.
But the extra fertilizer and water are very important.
@suzysparklesalot I have a volume listing rebloomers and where they have been reported to rebloom. If you send a list of the varieties, I can look up and tell you if there are reports that they will rebloom in your zone.