You could probably email and ask them for custom cut frame members. Although, the 1500 mm extrusions are only 59" so that may not be possible. also the 1000mm are only a little over 39." If you are willing to go 59.055118110236" x 39.370078740157" it should be a relatively simple solution. Here is a link for questions for the OpenBuilds Parts store. Contact Us Also, keep in mind that you loose the width of the gantry plates - at a a minimum - in your cutting area. More if you have a large dust shoe that sticks off to the side, or limit switches that are in the way of the gantry plates.
Screw drive systems like the lead system are limited by the usable length of the drive screws which is around 1 meter. If you wish to go longer than that you’re getting into custom territory as you’ll have to source larger diameter screws and fittings and work them into the system yourself. The big question here is what do you want the system to do for you. The bigger the system the more limited it gets in usability. What is motivating you to build a system this size?
Good point about the lead screws. If one were to go that large. I recommend these because you can source "OpenBuilds type" anti-backlash nuts. But then you get into new shaft collars, bearings, etc... Sharmstr did a good job documenting these mods in her build. Shawn's Workbee 1510
