A good ski resort
From Bucharest going North to the Carpathian Mountains, Fagaras Mountains more exactly, along Prahova (the river) Valley, in 100km you reach Sinaia then you climb more and reach Predeal, some km before Brasov.
Predeal is crowded in the winter as it's have nice slopes. It's a nice place also in the summer, there are so much accommodation to choose from, from hotels to smaller villas and recently luxury small hotels.
This is Susai lodge, 7km up the mountain, accessible in the winter only with 4x4 or by foot (two hour walk). The place is great for team-buildings as it has all the facilites. It's a big deal so don't expect a romantic loneliness :)

Winter
Trei Brazi