If 40 PSI is workable, than that would work.
I spend much more time boondocking and my water pump is 3.0 GPM at 45 PSI, which is plenty for me. Some 12 v pumps go up to 70 PSI 6.0 GPM.
The max the PEX tubing is rated for is 100 PSI.
The plastic interconnects for that PEX tubing I have no clue.
I found my house water pressure was 100 PSI and since then I installed a reducer.
A campground I stayed at I was warned that the pipe pressure was 135 PSI. I did use a pressure reducer.