Some exchanges like Binance, Bitfinex and Bittrex are the strongest exchanges currently available. I do not think there will be any problem holding your coins on these exchanges with a api disabled 2FA enabled account.
Although 2FA is used, i don't support keeping the crypto in exchange. First of all, there is a possibility of hacking, although it is the safest exchange. Secondly, the money in exchange is't exactly yours, you don't have the right to request for private key. Also, they can freeze your account at any time. Using offline wallet protects you in any situation.
