Hire a transit
You don't actually need a Transit, a fully built tandem will go in a Berlingo or similar as long as it doesn't have a solid bulkhead.
Or an RS6 with the rear seats down.
Or an RS6
I have a feeling the OP was looking for the cheapest way to shift a tandem, not the most expensive🙂
@Brommers started
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You don't actually need a Transit, a fully built tandem will go in a Berlingo or similar as long as it doesn't have a solid bulkhead.