That will depend on what the repeat for the wallpaper is. If it is straight hang it won't matter, but if there is pattern it will have to be matched up according to the repeat. It should say on the roll what the repeat is usually in inches. You could lay it out tonight if you have a space large enough to lay at least two pieces at a time to match your pattern. It would be a real drag to cut it all tonight to find out tomorrow that the pattern doesn't match.

Linda

Watch out...is there a repeat in the pattern?  You know....if the wallpaper has a fluffy dog every 21" and you want all of the fluffy dogs to line up from flat to flat then you sure need to leave a lot more than 4"-6" over the 8'-0".  If the pattern is little rosebuds it is easier.  I assume that your wallpaper is not as wide as your flats so you have to match up the pattern on at least one seam down the middle of each flat.  Better to cut the paper as you are applying it.  If you do screw up and cut all of the paper too short you can make horizontal seams...just make sure they are glued down well ( use a seam adhesive and a hard seam roller) and no one in the audience will ever see the seam.  I would use my time before " wallpaper night" making sure that all of the surfaces are clean, smooth, dry etc. and that there are plenty of supplies ready for your work party tomorrow.  Whay can't you start it tonight?  In my experience wallpaper is never " slap it up and be done"....it manages to slap me around instead.  Most important tool?  Sharp razors and clean sponges....good luck.  

This is slightly off topic, but I'm posting it here anyway...

I wanted a Victorian wallpaper look for my set but didn't want to go to the expense of wallpaper or ruin the flats by applying wallpaper.  Somewhere on this board was a reference to a site called http://www.rollerstencil.com - www.rollerstencil.com   which I decided to check out.  I located a set of these tools that someone was willing to loan us and we just used them today.  The results were great.  It didn't take as long as wallpapering would have taken and it was very easy to do.  It hardly used any paint at all and the best part is that we don't have to try to strip the "paper" off the flats!  When we have photos I'll let you all know.  I think it was definitely a success.

Our show hasn't opened yet -- I don't have photos yet, either.  But if you go to that site, you can see what the process is -- there is a video which shows it, how it is done and how it looks.  I think it would definitely be worth the investment to purchase a small set of these tools.  It really isn't that hard as long as you don't mind going up and down a tall ladder (I had a great volunteer!) and have someone to move the ladder as needed.