Conventional financing CAN work, if you want to go that route. An FHA 203K loan, is probably your best bet in this situation because you'd be able to borrow the rehab costs too and package it all in one loan with just 3.5% down. Also, FHA has a few more safeguards than conventional financing. Conventional financing can be easier to qualify for, and those loans are usually more lenient on the types of property they finance. If your cabin won't qualify for FHA initially, then conventional financing might be your only hope.