You would be wise to "regroup". You really do need 2 catchers + a multi position guy to fill in...And at least 6-8 PO, with backups. To compete at this type event, a roster of 18-20+.
Plan on HEAT & HUMIDITY! It will take a toll on these guys! You don't want to lose anyone to heat exhaustion (been there, done that with a catcher. NOT fun!) Keep 'em hydrated, potassium tabs & ice water cloths/towels in dugout.