You might want to consider a holiday for single or solo travellers. I have travelled with One Traveller, Just You, Saga Solos, and Riviera Solos. Although most of the travellers are widowed or single, there are usually a few who have a partner at home who is unable or unwilling to travel. There is always a predominance of women, so you'd have plenty of potential female companions, and because everyone is on their own, they're all likely to be keen to make new friends. You don't have to share a room, you get a double room to yourself - the prices tend to reflect this, but the headline price is all you pay, there's no singles supplement.