Weddingbee boards

hi all,

 I have my heart set on an outdoor ceremony in my parent's backyard (they live on a lake and its wonderful) but they also live on a dead end. With 200 guests in July in the Northeast, its turning into a logistical nightmare - what if it rains, where are they all going to park, etc? 

Another issue is that I'm not quite sure how to tell if there is enough flat space to seat everyone. Does anyone know some basic guidelines for this? how much space do you need for 200 chairs?

 Also, do you think using a website to let people know if there is a change of location due to rain is ok? We can call some of the older guests who may not be website friendly.

is this too much of a hassle for a 30 to 45 minute ceremony? my family thinks im nuts, but it would just be gorgeous! 

Thanks! 

can you rent tents?  then if it rained you'd have a backup.

or actually rent a backup - like a hall - and then if you know in advance the weather is going to be bad you can switch at the last minute. 

it's pricer than having one place all ready to go, but if you want outdoors its a good idea.  (if it does rain and you've only got the outdoors option you're s.o.l)