In general, the more North you travel and the more urban the location, the less on-hand cash you'll need. Obviously if you travel to more rural areas, then cash will asked for over credit. Small shops, street stands and small transactions, cash is usually preferred.
For my past trips, I withdrew about €300 prior to departure, that usually suffices for about 10-days. Depending on how my spending is going, where the trip is taking me, I'll do another withdraw about halfway into my trip. For a seven week trip, you're probably looking at maybe two or, three withdraws while in country; ATM fees aren't punitive or crippling. I'd avoid bringing over so much at once and having that amount weigh on your mind. Should you misplace or, have that amount stolen, even a fraction of that, is a lot, don't put yourself in a vulnerable position.