Advice needed please…

Hello!
I am after some advice please.,:
I’m getting married next year and with no wedding planner it’s a DIY wedding
I desperately wanted to get married in a location by the sea however, the place that is special to us does not have any registry office near by. Also I wanted something for the ceremony that was a bit different. So…. We’ve actually not told our guests that the wedding will be in 2 locations as we want the day to be a surprise and we are looking at hiring a vintage red bus to take them in between the venues… the only thing is in a vintage red bus it will take an hour and half …. Is this too long?? I’m concerned people will be bored.
At the ceremony venue there will be drinks and pizza as a snack so people are not waiting for food… usually there’s a bit of a wait between the ceremony and meal anyway…
Advice needed please for a bride that cannot ask her friends for advice because they don’t know either!!! 🙈