Needs better handling when with large number of nodes to prevent browser slowness and crashing

I have a site with over 100k pages. When in edit mode on page the node reference field will load the browser with all 100k nodes. This makes the page close to 10MB which makes the browser very slow to use.

The alternative is to use the Autocomplete option however the autocomplete has not limit on the data it will pass and if the user types 1 or 2 letters it crashes the browser because of the large amount of data.

The solution as I see it is to force the use of autocomplete once the amount of page exceeds a certain amount and limit the number of returned rows in autocomplete.

In my case I just changes line 485 from:
print drupal_to_js($matches);
to
print (count($matches) <= 50) ? drupal_to_js($matches) : array();

Of course it would be nice if the limit could be done through the form instead hard coded of as I have done it.