Hi, Guanabo should be fun. The thing with Guanabo is that there are many rental units and many of the casas have more than one room for rent. If it was me, and if I did not have much luggage to drag around, I would just get to Guanabo and walk up and down a street and find a nice casa, ring the door and ask if there is a vacancy. Even if the house is fully booked, the owners will usually call neighbors and find you a place.
Alternately, if you want something planned, you can just contact my assistant at casas.bestcubaguide@gmail.com and she can find and reserve you a good casa in Guanabo. You can see a couple of great places for rent here:Â https://bestcubaguide.com/casas-particulares-in-guanabo-cuba/
take care!