Advice on timing of vacation

My hubby and I are thinking of taking our last "just the two of us" vacation during the winter holidays. We will be somewhere between 17-20weeks along, depending on when we book.
Does anyone know if that time is still comfortable enough to enjoy a vacation? I don't want to be too morning sick still, or too big yet. Experienced mamas, do you remember what was the most comfortable time during pregnancy (if there ever was such a time for you 😀)?