A few years ago I had my pump fail suddenly and ended up waiting three days for a new one due to a shipping nightmare. I spent the first 24 hours of that taking only Humalog before I finally took some Lantus (my pump was supposed to arrive within hours originally).
Make sure you are covering your basal needs as well as boluses. Do a small injection every three hours or so with either just basal, or basal + bolus + correction, as needed. This will mean waking up throughout the night if you will be going for more than one day without the pump.
Or you could get Lantus, though the downside of using Lantus is that it hangs around for two or three days even after you’ve got your pump back. When I fianlly took Lantus I ended up having to wait for an extra 12 hours after I got my pump back to start using it for a basal rate, as the Lantus was still working.