I would restring before the tournament, especially if you're going to be playing singles (more likely you'll break a string than in dubs). You don't want to bust those old strings while you're playing and then have to adjust to another frame during the match.
Also, I can't imagine new but stiff-feeling strings not being a superior choice to dead strings that could break at any moment.
USPTA Certified, NTRP 4.5
Yonex RQiS1 Tour XL 95 with RPM Blast 16g