How long will ink last in an Epson 3880 Printer?

I currently use about 2 sets of ink cartidges per year in my Epson 2880.  The 3880 cartidges hold about 6 times the ink.  Therefore I would not be replacing a full set in the 3880 for about 3 years.  My question is, will this be a problem and how long can I expext the inks to last in the printer?

Thanks.