They wil be a bit stressed and maybe even have some minor leaf damage. Does it freeze where you are? If so, you might be in a bit of trouble should they get close to freezing in the dark for a few days. However, if you have a reasonable temp, I think you will likely be fine.
If you could get them in front of your house and turn the car's headlights on overnight that might work too
I did this some years ago. I didn't put them in my yard, but I did move them to the front of the garage and opened the door. We live on a completely fenced property in the middle of nowhere, so privacy wasn't an issue. I parked our two cars so that the headlights were shining directly on the plants. I ran each of the two cars for about 30-minutes on and 30-off with the lights on both of them all night. I'll never forget that crazy weekend.
In other words, think outside the box if you need to.
If noise/neighbors are not an issue and you are in the uSA then get to Costco and buy a generator. They will take it back when you are done with it. They have a fantastic return policy.