parti gyle brewing !!?

I'm new to brewing. Just started brewing last spring. I want to make a high gravity beer. So my thoughts after reading some things on parti gyle brewing is that maybe I could do a normal grain bill for a 5 gallon batch. Extract about two gallons off mash and boil off to create a high gravity one gallon batch. Then go back to the mash. Batch sparge for a five gallon batch of normal gravity.

Benefits to me is I don't have a huge pot to do a large enough boil for big beers. I could do this on every batch that I make and have a different high gravity beer everytime without too much extra costs.

Does anyone else think this a good idea or already doing this...

So my last brew was a stout with a og of 1.070. But also went back to my mash and batch sparged for a second time and got about three more gallons of wort. I then boiled that as new smaller beer with some corn sugar to boost gravity. I got a og of 1.050. I then used this as my first lager attempt. I think it should be interesting with a lager with a stout grain bill. If anyone wants to see my recipe I can post it