We got a letter 2645C. Once the 60 days is up will we be asked for more info potentially Or just get our refund? Just curious if it often gets drawn out longer.

There is no set time frame for this...it could end & it could be draw out longer ..on time will tell. 

Yes the time frame can be extended again. You could be asked for verification of income or the refund could be released. Check your return to assure all income was included and correct. If not you may need to file 1040X