If enough of the root structure is still intact, it might be salvageable. I usually use metal (tbar) stakes because they can be pounded in and don't take up a lot of real estate. I would make sure you have the tbar pounded in a good two feet or more for adequate support. You can also use wooden posts but to get them deep enough to support weight, you will have to dig a hole and bury the end of the post, tamping in the soil really well.
I have never tried straightening a tree that has blown over. I am just giving advice based off of transplanting a few fairly large trees over the years and supporting them until their roots can support them.