Upstate means the northern part of a US state, away from the big city in the south of it — and it is almost always about New York. 'She lives upstate' means she lives in New York State but well away from New York City. 'We drove upstate for the weekend' means north, into small towns, farms, mountains, quiet. It works as an adverb (go upstate, live upstate — with no 'to' and no 'in'), as an adjective (upstate New York, an upstate town), and loosely as a noun. Here is the thing dictionaries often make too tidy. 'Upstate' is not really a compass reading; it is a feeling about a place. For many New Yorkers, upstate begins wherever the city stops mattering, and where exactly that is depends entirely on who you ask — people who live an hour north will insist they are not upstate at all, while someone in Manhattan may call anything past the suburbs upstate. So the word carries an idea of rural, slower, cheaper, colder, further from everything. A few other states use it, most notably South Carolina, where the Upstate is the north-western region. But if you meet the word with no state named, assume New York. This is American English. It is not used in Britain, and it means nothing in a country that has no states.