Bigger than A3? Like in "A2" or similar? That is quite big.
I can imagine only a couple of models that would really require such large format. And experience has taught me that the bigger a single part is, the more troublesome it gets in every sense.
Maltedfalcon is right about the way to split parts in two or more A3 pages, and then joining them with a strip. That's the more sensible way to go for bigger parts if you are printing A3 or double letter in a laser printer.
As a designer, you have the freedom to try and design in any format. But if you plan to sell or distribute your designs to the general public, consider that not all modelers have access to huge format printers. And only recently A3 home printers have started to appear in the market.
If you are designing your model as a personal project for yourself, and really really really need to print bigger, another option is to look for a big format professional service, and to print in a color plotter. However those are ink prints (not laser). So the quality of the finish may be different. but you are definitely not restricted to page size, as it can print on rolls of paper 2 meters (6ft) by whatever length you need.