Another vote for for 10x8 doors. My full size van barely gets through a 8' wide door, maybe 2-3" mirror clearance on each side. No excuse for 7' tall doors on any garage much less a 30x45. A 10' wide door will give much more wiggle room and clearance for a 8.5' wide trailer. Don't worry about symmetry or exact spacing, it's a garage and you will soon forget about it. Adding a stud or two between doors isn't a problem.
This forum is full of "how can I make my doors wider" (or taller) threads, I haven't seen anyone wanting to make them smaller.
A 12' and two 10' doors might be my choice and it would still leave room for a pedestrian door. The building dept. anticipates changes from the plans, moving/enlarging doors and windows happens everyday. They are more worried about proper structure and if you do it to code they won't even raise an eyebrow. Run the changes by them if that makes you more comfortable.