Catholics- Special circumstances marriage before a parent does??

Katie
Hi. My fiancé's father has a leaking aortic valve and is not expected to make it much longer, it could be a day or a week or a month, we just don't know. Our wedding date isn't until May 2, 2015 but his sweet father wants so badly to see us get married before he passes away. We are going to keep the May 2nd date but we want to get married now so his dad can be a part of it. Does anyone know if a catholic priest will perform a ceremony under these circumstances? We weren't scheduled to do our pre Cana class until January but this is extremely important to us. Any advice?