... do you think we would be able to plug into 30A outlets at RV parks wihtout incident? Are such outlets 120V and not 240V?
Shop is the expert in this department. Any others out there?
tt-30p is a 120 volt item.
which explains that this adapter won't work but can be re-wired to work.
First of all, if you are at any modern RV Park today, they would proudly advertise "50 Amps hook up" which means for your included Tesla NEMA 14-50. That's 240 volts, 50 Amperes.
Which means you do not need to buy anything else.
Just pull the included Tesla out and you are all set!
Your adapter is to hook home 240 volt 30 Ampere dryer outlet to your included NEMA 14-50.
The problem with that hook up is, your Tesla expects 50 Ampere source but your adapter source is from only 30 Amperes. That would trip your home circuit breaker because it's rated 30 Amperes, not 50 Amperes. In that case, you have to remember to manually turn down your Tesla charging Amperes down to 24 (80 percent of power supply.)
Sorry. My dryer outlet info is incorrect as pointed out by @d_kaufman.