Maybe your terminal doesn't send resize events? I tried it on macOS 10.12 in iTerm2 v3 and Node.js 6.2.2 and it worked as expected.

I put the following in the Node.js REPL:

process.stdout.on('resize', () => {console.log(process.stdout.columns, process.stdout.rows)})

And this is the output:

WriteStream {
  connecting: false,
  _hadError: false,
  _handle:
   TTY {
     bytesRead: 0,
     _externalStream: {},
     fd: 10,
     writeQueueSize: 0,
     owner: [Circular],
     onread: [Function: onread] },
  _parent: null,
  _host: null,
  _readableState:
   ReadableState {
     objectMode: false,
     highWaterMark: 16384,
     buffer: [],
     length: 0,
     pipes: null,
     pipesCount: 0,
     flowing: null,
     ended: false,
     endEmitted: false,
     reading: false,
     sync: true,
     needReadable: false,
     emittedReadable: false,
     readableListening: false,
     resumeScheduled: false,
     defaultEncoding: 'utf8',
     ranOut: false,
     awaitDrain: 0,
     readingMore: false,
     decoder: null,
     encoding: null },
  readable: false,
  domain: null,
  _events:
   { end: { [Function: g] listener: [Function: onend] },
     finish: [Function: onSocketFinish],
     _socketEnd: [Function: onSocketEnd],
     resize: [ [Function: onresize], [Function] ] },
  _eventsCount: 4,
  _maxListeners: undefined,
  _writableState:
   WritableState {
     objectMode: false,
     highWaterMark: 16384,
     needDrain: false,
     ending: false,
     ended: false,
     finished: false,
     decodeStrings: false,
     defaultEncoding: 'utf8',
     length: 0,
     writing: false,
     corked: 0,
     sync: false,
     bufferProcessing: false,
     onwrite: [Function],
     writecb: null,
     writelen: 0,
     bufferedRequest: null,
     lastBufferedRequest: null,
     pendingcb: 1,
     prefinished: false,
     errorEmitted: false,
     bufferedRequestCount: 0,
     corkedRequestsFree: CorkedRequest { next: null, entry: null, finish: [Function] } },
  writable: true,
  allowHalfOpen: false,
  destroyed: false,
  _bytesDispatched: 5873,
  _sockname: null,
  _writev: null,
  _pendingData: null,
  _pendingEncoding: '',
  server: null,
  _server: null,
  columns: 343,
  rows: 25,
  _type: 'tty',
  fd: 1,
  _isStdio: true,
  destroySoon: [Function],
  destroy: [Function] }
> 343 26
> 343 27
> 343 28
> 343 29
> 343 30
> 343 31
> 343 32
> 343 33
> 343 34
> 343 35
> 343 36
> 343 37
> 343 38
> 343 39
> 343 40
> 343 41
> 343 42
> 343 43
> 343 44
> 343 43
> 343 42
> 343 41
> 343 40
> 343 39
> 343 38
> 343 37
> 343 36
> 343 35
> 343 34
> 343 33
> 343 32
> 343 31
> 343 30
> 343 29
> 343 28
> 343 29
> 343 30
> 343 31
> 343 32
> 343 33
> 343 34
> 343 35
> 343 36
> 343 37
> 343 38
> 343 39
> 343 38
> 343 37
> 343 36
> 343 35
> 343 34
> 343 33
> 343 32
> 343 31
> 343 30
> 343 29
> 343 28
> 343 27
> 343 28
> 343 27
> 343 26
> 343 25
> 343 24
> 343 23
> 343 24

On resize it reported the visible size of my terminal showed on my 3400x1440 ultra wide screen display.