Cycling route around Faithlegg Waterford

You'll have no problem with finding "bit of climbing"......in fact there is a climb that touches 21% just outside the front gate of the hotel ! I'd go further to say that its pretty much all up & down in the area and you will do well to do less than 600m of climbing in any 80km route that you pick. Probably bring a bike with decent tyres, 28mm if you can and maybe mudguards as the roars in the are can be pretty........mixed, esp. in December.

A loop into Cheekpoints and back via Passage East, Dunmore East and Tramore, perhaps on to Fenor ann then over as far as Kilmeaden and back via Waterford city will see you close enough to 80km (and 800m +).

Alternatively take the ferry across the river from Passage East and there is another monster hill right at the pier on the Ballyhack side (18% or so) and lost of options for loops towards Hook Head or just sample a bit of the area around Duncannon and then back to the ferry and pick up some of the above route to get up the KMs

Another option similar to @exiled1 suggests would be to head to Passage East on to Woodstown and then over to Tramore and out the copper coast road to Bunmahon returning back towards Waterford via Kill and Kilmeaden will throw in plenty of short sharp climbs to make toy feel like it was a recce for Liege Bastogne Liege.....

Lots of options. Choose on the day based on the wind direction as the roads can be heavy and it can be very blustery along the coast.