I had a customer come in the other day that we were installing a new roof top AC for him. He travels with a number of show dogs and told me about an affordable device that will monitor Temp, Humidity and even more important loss of power. For all the pet owners and folks that may need to leave their RV unattended for periods of time this might be a relief.
The unit is plugged into any house current plug and when the power goes off or the temp rises or falls to a preset number- will call,text and email what ever contact you enter in your account. It doesn't use the Internet but has its own cellular device that uses the Verizon network. You can see live readings from any computer or there is a smart phone app that allows you to adjust setting on the monitor remotely.
Found it on Amazion for $199.00. Monthly service for $8.00 a month with a yearly contract or around $14 month by month.
I worry about my dog especially in the extremes of the seasons and this so far has been a great buy.