The risk premium would increase greatly in a major crisis. Look at the US downgrade in 2011. The risk premium would expand in a really bad situation, and the result would be that the government would have to print money to cover the insurance. So, yes, you'd get your money back, but it would be money that is worth less than what you had in the bank.
That's likely true, but at least you would get something back.
Another interesting point to consider is that major crises are usually accompanied by deflation (at least part of which is a result of debt destruction). So the inflation caused by printing dollars to cover bank deposits might be at least partially offset. And the good thing about the inflationary part is that the dollars would be going more toward the working/middle class instead of the rich, which would keep the economy going better than giving banks bazillions of dollars.