I agree with Christopher. Adding to his comments, a lot depends on what you are comfortable with.
Looking at the house side of things. My 'comfort' required a plastic utility sink, fresh/black tanks (and ability to fill/dump), toilet, small battery bank/monitor, inverter, window coverings (cheap material hung with sticks/screws), mattress on floor, refrigerator, microwave. The plumbing and electrical systems were built with the big picture in mind, from the start. That included shore power cord, automatic transfer switches, breaker panels, etc.
I very quickly grew tired of living out of boxes and that served as a great motivator to keep moving forward with things. The negative of this approach, as you probably already know, is having to do work out of order. There are many things I would like to do over again because of this.
I can imagine that this 'build as you go' approach does not work well for many. I am lucky to have basement space to carry a table saw, radial arm saw, lumber, chop saw, small welder, and a bunch of other tools. I am also able to power these items from the coach/battery (not the welder) while sitting in the middle of the forest. Oh, also... I spent a good part of the first several months (of living like this) sitting on the property of family and friends so I often had a shower and shore power.
I still don't have heat or A/C installed.