Depending on where you are going, there may be places that take cash only, also some smaller hotels will give discounts for cash that might be worth it. I usually try to estimate my costs for 2-3 days at a time so I'm not withdrawing amounts too often or carrying large amounts of cash on me for longer than that. I usually only use my credit or debit cards for large purchases (rental cars, train tickets, hotels, higher priced restaurants, etc.) and use cash for most smaller purchases (markets, small souvenirs, entrance fees, small cafes/coffee shops/snack stands, etc). It seems like almost everybody has their own system for cash vs cards that works for them - I always tend to lean toward more cash and less cards, but that's just me.
I agree with the above poster. You don't necessarily need to switch financial institutions (I didn't) but you might want to open a credit union account just for travel expenses, or set up an online bank account for ATM withdrawals only (not credit cards). I actually set up two online bank accounts (Ally Bank and Capital One) so my travel funds were spread about and I wouldn't lose everything if a card got stolen or hacked. It was easy to move money from my normal bank account into one or both of these accounts if/when I needed more available funds. Worked well for me.
