general advice imo is to avoid anywhere that you need jabs or mosquito pills for. florida was perfect for us nov/dec as it wasn't too hot around mid 70's. would also avoid really hot countries personally but then you might be a more confident traveller than me. I could make more suggestions if you could say what your budget is, what kind of thing you like etc.
South Africa. Direct flights (BA, Virgin etc.) are overnight, so DD will sleep and you won't have to worry about her running around the plane, or having to keep DD entertained. If you're lucky, you might get away with squeezing her into a skycot so might not need an extra seat. Plus the time difference in South Africa is only an hour or two, so you won't have to deal with a jet-lagged DD whilst jet-lagged yourself. And South Africa is beauuutiful. We went with 7 month old DD last year and it worked really well.
The beach in punta cana (dominican rep) is fab but its all inclusive resorts and not much else to do. Am thinking varadero in cuba us equally beautiful and lits to see but that would involve a couple of nights in havana to make the modt of it. Riads are not great and you dont want to do long day trips.
Are you keen on boating/sailing? Why not consider a small cruise ship island hopping?
Dubai is an easy option. Good hotels, pool scene and service. The beaches are just OK. Definitely more in terms of entertainement if feel you need the distraction A good Plan B. Oman and muscat have fantastic beaches from what i've heard but little else to do.
How about Miami south beach? Great beaches,great food and a funkier vibe. Easy to get around with a stroller. Again like in the caribbean, if you go very early Nov. you might get caught in the tail end of hurricane season.