In Teneriffe you have an apart-hotel with 3 swimming-pools and one of them with a terrace for naturists but not a specifical naturist resort.
Now in Gran Canaria the wide circular island you have a naturist resort, in Maspalomas south the island. In winter the temperature¿ll seldom fall below 21¿C(70¿F). In front of the resort you¿ve the wonderful dunes of Maspalomas.
Becareful to book earlier in February ¿cause it¿s carnival time and all hotels and resorts are full but you won¿t regret to be there, I¿ve been and I loved it, both, carnival and to do nudism on the dunes.
Hope I could help you a little.