A helper tampermonkey script allows drag the sketch document.

Sketch Measure Helper.js

// ==UserScript==
// @name         Sketch Measure Helper
// @namespace    http://tampermonkey.net/
// @version      0.1
// @description  try to take over the world!
// @author       You
// @match        file://*/*
// @grant        none
// @run-at       document-idle
// ==/UserScript==

(function () {
    var target = jQuery(".screen-viewer")

    target.on("mousedown.sketch-measure-helper", function(e) {
        var MOUSE_BUTTON_LEFT = 0
        if(e.button !== MOUSE_BUTTON_LEFT) return false;

        var initX = parseInt(target.scrollLeft()) || 0;
        var initY = parseInt(target.scrollTop()) || 0;

        var downX = e.clientX;
        var downY = e.clientY;

        target.on("mousemove.sketch-measure-helper", function(e) {
            var left = initX + downX - e.clientX
            var top = initY + downY - e.clientY

            target.scrollLeft(left);
            target.scrollTop(top);
            e.preventDefault();
        });

        target.on("mouseup.sketch-measure-helper",function() {
            target.off("mousemove.sketch-measure-helper");
            target.off("mouseup.sketch-measure-helper");

            e.preventDefault();
        });

        e.preventDefault();
        return true;
    });
})();