surge protection with amperage adapter

I am in process of buying new RV with 50amp power. I have a 30amp outlet wired on side of house. (Don't plan to stay buy another year, so not changing). I sold the 30 amp surge/EMS unit I had when I sold my previous 30 amp RV.

If I use a 30amp male to 50 amp female adapter and then portable surge/EMS unit (probably Progressive Industries EMS-PT50X Portable RV Surge Protector - 50 Amp ), is the 50 amp unit suitable protection?

I am sure there may be other times, that I run into sites that are only 30 amp, but as I am preparing to full time, I don't want to buy lots of unneccessary "Stuff".