In Scandinavia, the typical length of a VC fund is actually 10 years with a standard option to extend for 2 years. First half (5 years) for new investments, second half for followups and then 2 years for padding (option to be exercised at the management company's discretion, not the LPs). I would assume a similar setup is common overseas.

So if you're part of an investment out of a young fund then you typically have at least a 7 years time horizon. Obviously things have to go well in the meantime or they won't sustain you for that long. But the difference between a Marc Andreesen VC and any other VC is def not the length of the fund.