I bought the Mrs a cupholder from Librands. It sits under the seat permanently. On the odd occasions she brings a hot drink out with her, she prefers to hold it in her hands and/or spill it down her front.

Cupholder would be the smallest problem but the lack of internal luggage space and first of all the lack of money

Got a whole ton of luggage space. Money, not so much

Very neat solution if you don't need the rear seats very often for touring