Hmm, the only time I had wished mine had more clearance was when I went over a smooth side walk and didn't know the other side had a 6" drop. Kinda went over a little too fast and took a pretty good hit as the frame scraped on the concrete.
I thought I messed something up because when taking it out of park it felt stiffer than usual but after a few hundred miles it's back to normal now. Fixed itself... Isn't that what a toyota should do anyway?
If there is a will there is a way. How much more do you want. I would start with a taller tire if you can find one. Maybe go to an offroad shop and ask. They should know by looking at the car what you could do.
You can buy these little rubber mount at canadian tire that is made for adjusting ride height, cheap way to lift half an inch but I wouldn't recommend that, other thing , if you have 14's as your rims, theres an option for 15 rims and it lifts the car up a tiny bit also, other then that, I don't think anything is possilbe for suspension wise, but you might be able to fit the springs of an older corolla since the are almost the same. But i most definately dont recommend that.good luck and remember, burn rubber not your soul.
If you really were going with a lift, I would buy an early Japanese car with a real four by four system. In my area alone, I've seen a lifted Subaru gl wagon and a early lifted civic wagon. That is your best bet, while getting thirty mpg.