While BiPAP machines are rarely available in the small travel sizes CPAP machines come in, many BiPAP machines are small and lightweight enough to tuck into a suitcase.
If you plan to use your BiPAP machine while traveling, it may be worthwhile to choose a model without a humidifier. BiPAP machines with integrated humidifiers are larger, and an external humidifier accessory can detach and be left at home when you travel. You may also want to ensure your BiPAP machine is compatible with an external battery, particularly if you plan to camp or travel in areas without electricity.