My boyfriend and I are going on our first long road trip from Phoenix, AZ to East Lansing, MI at the end of July. Google lists two options - I40 and I80. Both are estimated around 30 hours.

Questions:
What is the realistic time we should give ourselves? I am not sure if I can trust Google. Originally, I thought I could do it one shot but after reading some of the other posts I think that may not be realistic.

Trying to get to Phoenix as soon as possible - maybe 2 to 3 days. Is that even possible?

Thank you for your help!