I'm on PSE6 but I should think this works in PSE7 too........
I use an Epson 4000 printer, by the way, 17" wide.
Just go to the Organizer. No idea why, but it seems this can only be done there and not in the Editor.
Select the picture you want to print. Go to File > Print. Hit the Page Setup button and choose your printer, paper source and paper size. If you select your large printer, make sure that the Paper Source is checked as Roll Paper. The dimensions, however, can get tricky. I have a 17" wide printer and can select the "US C 17" x 22"". (This won't do all your prints in one job but will probably be ok for 11 at a time at 4"x6"). The alternative is to put in your own paper size or, as I've found, just click on "User Defined". It may be safer to stick with an actual size, like the 17" x 22" - that should give you 11 photos per sheet at a time and is probably safest - you don't want to have a problem and find that the printer will continue printing 12feet of paper before it stops. You mention having a 16" wide roll of paper - that may be difficult but try the "Borderless" checkbox and see what you get after you do the next bit.
In the main Print dialogue box you will find three items to be checked:
First is the printer you want to use.
Second is the Type of Print. You will want "Individual Prints" - yes, not very intuitive, but that's Adobe.
Third section is the important part...... "Select Print Size and Options". Choose the dimensions you want. Then there's a checkbox for "One Photo Per Page" - obviously, leave this unchecked. Now here's the big one.....
"Use each photo ..... times", with a dropdown selection box. If you keep raising that number, the number of pages may well go up. From here on it's a case of "try it and see".
Now, you will get different numbers onto the paper depending on what size paper you put - more if you have put "User Defined" Dimensions in the Page Setup, as above.
Then there's a "Crop to Fit" box - leave unchecked.