In December My Mom's Side Of the family is coming down to our house to celebrate my Grandpa's 70th Birthday. It happens to be at the same time as christmas.
I wanted to make a golf cake for my grandpa but i also wanted to make a christmas cake. I also had the thought of doing a two or three tier cake and have each tier be celebrating something different like golf and chrstmas. Unless that might look too chaotic. Another thing is that I want to spend alot of time with family not too much with cakes.

What should I do?

Personally, I'd find a way to combine the themes. Such as having a Santa holding a golf club, or something similar.

Check out these pics of Disney's Winter Summerland mini golf course. Maybe some of those images will give you a good idea?

http://images.search.yahoo.com/images/view?back=http%3A%2F%2Fimages.search.yahoo.com%2Fsearch%2Fimages%3Fei%3DUTF-8%26p%3Ddisney%27s%2520winter%2520summerland%2520miniature%2520golf%2520course%26fr2%3Dtab-web%26fr%3Dyfp-t-501-s&w=305&h=228&imgurl=www.disneyclubs.com%2Fgolf%2FIM001633.JPG&rurl=http%3A%2F%2Fwww.disneyclubs.com%2Fgolf%2Fwinter_summerland_photos.htm&size=19.9kB&name=IM001633.JPG&p=disney%27s+winter+summerland+miniature+golf+course&type=JPG&oid=f412c5a0077a43bc&no=4&sigr=11sasjv30&sigi=115a0fdio&sigb=14d6j3t45&tt=6

I agree....make the golf cake, Christmassy. You could have a golf cart with Christmas Lights. The person in the cart wearing a Santa hat. The trees could all have Christmas lights. If you lived where there would be snow you could have the golf course snow covered. If you decide to do a tier cake, I would make the top cake winter golf and the rest Christmas. I think you would need something in common on each tier to tie them all together.
Sounds like a really fun cake to make to me.

My own personal opinion would be a big golf cake for your Grandpa. Everyone is coming down to celebrate it and 70 comes around only once! Make it extra special for him and he'll appreciate it. Then you can make a little Christmas cake but the 70th should be the showstopper.

Good luck with what you decide!