Electric Snake Use

I have a main drain which clogs periodically. The location of the clog is typically about 40-45 feet down from the roof vent. Rather than continue paying Roto-Rooter et.al. $100+ a pop, I have been considering renting an electric snake and routing out the drain line myself. Problem: The snake weighs around 70 lbs. and , being a bit long in the tooth, I don't think I could lug it up on the roof on a ladder to use the roof vent for access (which is the way Roto-Rooter et al. do it). The bathroom in question has a sink, toilet and shower all of which feed into the main drain upstream of the clog. To reach the clog, can I run the snake through the shower drain which is easily accessable and, being on the ground floor, would pose no lifting problem??
Also, I can rent a Rigid manual snake with 50 ft. of cable, which I can probably wrestle onto the roof - no heavy motor - if this would be a better alternative.

Running a sewer cable down through a trap rather than a straight large diameter pipe robs you of two things:

Torque at the end of the cable where the machine does all of its work

Limits the size of the cable needed to effectively clear the obstruction


Pulling the toilet would be a better suggestion than going to the roof.

The closer that machine operates to the clog, the more power that machine has to remove the obstruction.

Hire a plumber to install a cleanout on the main, somewhere accessable.

drain

Dig down to the pipe outside the house where it exits the foundation and have a plumber install a cleanout there. If yours is the typical house the roof pipe is 3", but the main sewer line is 4" so you cannot do a proper job of cleaning it from the roof anyway.

Additional Data

Some additional factors bearing on the problem:
W/R/T pulling the toilet. Awhile back, I had a plumber look at pulling the toilet so that Roto-rooter could run a larger auger down the drain. He was reluctant to try it since the toilet rests on a tile floor and there is a grout seal around the base of the toilet. He was afraid the he could not pull the toilet without damage.
W/R/T installing a 'clean out' in the main drain. There are two very large Shiffelera trees occupying the space where the drain exits the foundation. Without having to dig up big trees the 'clean out' would have to be placed in the yard at least 10-12 feet or more away from the foundation, probably on the downstream side of the clog. (No, so far there has been no evidence of roots causing the clogs, but next time it happens I'm going to have a camera inspection). Can you put a 'clean out' away from the house and run the snake the other way??
W/R/T using the shower drain. There is no trap in evidence .The drain from the stall shower seems to go right into (and through) the floor of the house, connecting with the sink and toilet drains ,to the main. The only disadvantage would seem to be having to run through a 2 inch line to get to the 4inch main drain. Is this totally futile??
Finally, what is the consensus W/R/T using a manual snake through the roof vent??

Pay to have sewer camered

maybe roots, or cracked clay,ect. fix the problem! Or buy stock in R. R.