Some areas build with only 7' door openings. In some areas, the prefererence is or the homeowner specifies an 8' door. Many savvy homeowners with the funds to do so build with 9' doors.
So, it just all depends. The term "standard garage" is a bit mis-leading. Measure both garage opening, interior garage height and decide. Over all outside height of the trailer is provided by the manufacturer in their specs.
Of course, if you're close, there are ways of gaining 3 or 4 inches by defating the tires
, removing the tires
and/or using lower riding car dollies.