The toasts may well be 90% more important than anything you are going to do in the remaining time.Try not giving them a microphone and see if it only has a 10% impact on the review you get. "...it isn't going to ruin the event" is hardly the standard of care and due diligence a customer wants to hear from their DJ. This is not an unforeseen circumstance.
If you only intend to bring two speakers - then what are you... a rental agent? We know in advance this room has issues - so you resolve that issue by bringing another fill monitor. If you're so cheap that you can't bring a powered Eon or equivalent (which you should already have as backup anyway) then what is your reasoning to nickel and dime what should be simple professional foresight?
The important thing is: what needs to be accomplished? - and can this be done well with a given setup. There are only 8 tables shown which means the guest count lies somewhere between 48 and 80 people, with up to 2-8 more at the head table. No doubt there is more than enough sound to blow everyone away no matter where you put the speakers. Sound is not really the issue in this room - the real issue is the work-flow. If the DJ is hired for his emcee skills and works alone - then his setup needs to be near the front and not on the opposite side of the room where he walks back and forth all night like a bell-hop. If he is an "entertainer" and not just a DJ then he needs to be part of the visual - not hidden away.
From experience, and not conjecture, for the size of this room, 2 speakers in the back is not an issue. If one chooses to add additional speakers, fine and dandy. And I don't know any DJs who set up aside the head table in the front.






