A car is really a personal preference. I would go crazy without wheels as long as that training event was. However I also knew I would most likely be in SLC for sim as well. If you have sim elsewhere, driving your car that distance is much more of a gamble.

I bought a gym pass elsewhere in town and worked out most days of the week...I'd do that right after class most days, and then head back to resume study for the evening. Or study elsewhere... the SLC library, parks, etc work. The hotel drove me nuts after being there too long. I shopped for fresh produce, took my bike along for a couple of road rides, and managed a few hikes in the mountains.

"Is there time?" ... there is just barely time, and it depends on where in the foot-print you are and whether its your first 121 training event. There will be a solid week of systems where you are overloaded. That is normal. Like any training event it needs to be something you are devoted to completely. My ability to study and retain goes downhill at a certain point and exercise / good diet helped me to keep my head on straight.... so I am happy I drove the car out and would do it again.