It looks like maybe you should drain your block and acc after wards unless you use the -100 antifreeze, depending on where you are located. Here are some interesting facts to add fuel to the debate

Now, a thing or two about freeze protection:

Most people assume that the freeze rating on the jug of anti-freeze meant that you were protected to that temperature (e.g., the anti-freeze did not freeze until that temperature was reached), The fact is, winterizing products are rated by burst protection and not freeze protection. So when we say that an anti-freeze solution will protect our copper plumbing pipes to -50 deg F, it means that a copper pipe filled with this product will burst at -50 deg F. The actual solution will start to form ice crystals at approximately +12 deg F. As the temperature drops, the solution continues to form more dense ice crystals and expands. As the solution expands, it puts more pressure on the pipe and at -50 deg F, the pipe will burst. A PVC pipe will burst at -15 deg F since it's not a strong as copper pipe.
Since a stored engine is not being used, it is not necessary to keep the system ice crystal free, only to keep it from bursting at a rated temperature. While you can buy more expensive, lower rated antifreezes, you really only need to protect yourself from burst pressure. By the same token, why not spend a couple of extra bucks buy the lowest rating available (especially given the result of a miscalculation). It's cheap piece of mind considering the cost of miscalculating your needs.