Are you in the US, or UK firstly? Surely if you have a baby under 1 you'd be wanting to minimise flight time. I'd want somewhere that's warm, sunny but not too hot, a good resort with restaurants and entertainment and by a nice beach with clear shallow water for swimming in. If your're in the US, what about the Caribbean or if your UK, stick to Europe
Am in the UK, sorry should have said! Would have to exchange the dollars if going to a country that did not utilise it as currency. Ideally we would go somewhere that does however open to alternative suggestions. The Caribbean would be lovely but not with such a young baby.
Id exchange your dollars for euros you'd probably get a better rate than dollars to GBP's and I'd go somewhere nice in Europe like Spain or Majorca or even Centre Parcs. Failing that I'd wait till your baby was a few years older and put it towards Disney Florida