Yes we took off the front wheels and the bike took up two seats.
You need to coordinate loading a sitting as it’s a bit tricky.
With 15 bikes you could use 6 rows. One bike on each side of the isle so 2x 6 would be 12 bikes. You could get three to 4 bikes in the isle.
You can use the under storage if the bags are packed. The space is very large. You could pack coolers and tents too.
They should have dimensions available. Our cost for the bus was $1200 per 24 hours. But the university had a deal. So check with the athletic department to see if the univ has a contract. Maybe you could meet up and look at it in person.
It was great but we always arrived early to make sure we had parking.
Kim