It is unlikely that any 15 would ever take as much as 2 2x10AV's would. I truly think overlooking those 2 cabs is silly, I think it is actually your best choice. Although, the 2x12 option is cool, most likely less expensive and if you get 2 2x12's can have an 810 at one jam spot and a 2x12 at each of the others ... Then you can choose what to bring to your shows depending on the size of the venue and your volume needs for that show. If you go the 2 2x10 route you can only ever play the 2 of them together.
While JimmyM is right that the VR will be putting out more than 1/2 of it's total output at noon IME you will know when the 2x10's are getting close to all they can handle ... Let's say you can turn the VR up to 10 o'clock into the 4x10 you will probably be pushing 200 Watts at either 4 or 2 Ohms, they will take that as each is rated at 200 Watts at 8 Ohms. If you want to know how loud they will be, plug the VR into the top half of your 810, you can run it with a 8 Ohm draw for a few mins to see what it sounds like without any damage at all, start with the master volume at 9 o'clock and slowly turn it up to 10 and then 11, see if you can get a bit OD out of your head before you hear the speakers start to complain.
EDIT: I just hooked up my SVT II (non-pro) to the top half of my 810 and could turn it all the way to 3 o'clock ... I am honestly convinced that 2 2x10AV cabs could take whatever you feel comfortable with sending to them. There are 2 factors that could make your experience with your SVT VR and the top half of your 810AV ... 1) Your head should stay cleaner than mine would because the II (non-pro) is known to breakup a bit earlier than the VR, However, 2) I have KT88's instead of 6550's in my head which should give me more clean headroom ... Try it out see what you think. You can use the 2 2x10's at jams and the 810 at shows, if ever the 810 isn't enough, you can stack them all up and make a 12x10 that runs at 2 Ohms and will easily take all 300 Watts of the VR, LOL. Cheers.