Thats a beautiful large plant. It would be a shame to divide it but it looks like it has really outgrown its pot.
Is that a clay pot? If you dont want to divide it and simply repot into a bigger pot, you can break up the clay pot to free as much of the roots as you can.
If some of the roots are clinging to the clay too tight, its no problem - just bring that clay into the new pot. It will act as part of your new potting mix.
Now, if you do want to divide it I suggest the following:
Study the plant carefully and determine where you can cut the rhizomes.
On a large plant such as this, ideally you will want to have division clumps of 10 or more pseudobulbs per division so that the new divisions are still relatively large plants. This ensures that the new divisions will not miss a beat and bloom again the next season.
Cutting the plant up into so many smaller divisions might result in too much trauma for the plant and it could sulk for a few years.
So, divide them into bigger chunks initially. And if you want to divide again, you can do it the following year. It is better to end up with bigger divisions that you can further divide later. If you cut them into smaller divisions on the first try - you will not be able to put them back together