Even 60,000 GPU years sounds well within the capabilities of a large nation-state. Expensive, probably not worth it, probably better ways, maybe not practical, but certainly possible.
Practically speaking you'd hope that something that anyone would be willing to spend 60k GPU years on cracking would not rely on plain MD5.
If you still are feeling bit iffy, then you can easily throw another word in. Or use bigger dictionary; 6 words from 40k word dictionary gets you about 90 bits of entropy, which takes in the order of 10^9 GPU years to crack. That should certainly be enough, even if you account few orders of magnitude for ASICs and other general near-future improvements in crack rate.
Practically speaking all you should be worried about is your password being discovered within a stolen password hash table.
Nobody processing a whole table is going to spend that much time on your password specifically. If the government wants your data, or someone is willing to spend that many GPU cycles to get at your data, they probably have better ways of getting it.
