My advice would be to wait or just cripple your self for a month, either or
Tyres will need changing at some point....However the wheels will be a pretty permanent purchase...
Honestly, get the wider wheels, you'll be much happier for it
A what if scenario - You buy these wheels, transfer over old tyres...and out of sheer bad luck....someone slashes those tyres...you'd then have to go out and buy new tyres any way