There are a number of canvas tipi makers out there.Ranging in price from750 to 2000 dollars.Depending on how big you want it.That's just the canvas.For a family a whole summer you should have at least a 20 footer.That's measured accross the bottom of the tipi.Good luck making your own.You want a nice tight fit to the poles when you get her set up and that takes knowledge.Then you have to make the inside liner too because without that your tipi won't draft properly and it'll be like sleeping in a corn crib alley way filled with smoke.It really is a magical transformation of the use of mother natures elements to exist.A tried and true evolved over hundreds of years for efficiency shelter.A tipi is egg shaped at the bottom.Not perfectly round like some people think,and there are different styles also according to different tribes.A three pole set and a four pole set.Leaving a canvas tipi up for six months at a time will take it's toll on the very best of canvas.Another thing also it's the best durable in windy weather canvas shelter there is.It's round and wind has a hard time getting ahold of it.If you do this get the best straightest smoothest poles you can get.Lodge pole pine,spruce,or good fir.They are nostalgic to camp in that's for sure but I'm sure you would be hardening yourself up after six months.
To get you more familiar with tipis I'd suggest getting the series of the Books Of Buckskinning.I think there are eight out there at this time.
I've personally camped at many a rendezvous with an 18 footer and at this time use a 12 footer hunting camp type.18 poles are needed.15 for the set up,two for smoke flaps with one extra.An 18 footer will sleep 3 people comfortably while a 12 footer will sleep one and maybe two.