I don't think its worth the space it'll take up. I've been through severe power outages over the years with varying levels of success. 10g, 5 days, everyone but a single magical cory turned into a popcicle in 38deg water. 150g, 2 days, no one was even phased.
I guess the point is, your success during an outage totally depends on tank size. but either way, I don't see 1 extra hour of power as making any difference. they're fine without for that long, and if it's longer, that hour won't help.