Simply monitoring max/min won't cut it for the OP...since the dogs are in the TT he needs to know in real time if the temp exceeds limits. There are wireless devices that you can connect where it will notify you via text message if the temp exceeds the limits...BUT...you need to be in area with reliable cell coverage both at the CG and at the event where you will be. You also need to be able to receive text messages, ie if you are at a loud event or in a bid enclosed convention center reception may not be good and/or it may be difficult to monitor your phone.
You also need to consider that you need to be prepared to leave the event should you get a temp warning.
Have you considered boarding the dogs at home? If we have a trip planned like this with a lot of sightseeing or away time form the CG, we wouldn't take the dogs with us....for a few $/day you can board them at a kennel by your home. They will be well cared for an you don't have to take a risk leaving them in the TT all day.
