Missing right of way: Do road construction and development costs pose a threat?

With the proposal to approach the municipality about the 4 meter extended Eichendorffstraße, this idea already occurred to me when the separation of the community of heirs was still a speculation.

I would be interested to know what you think (regardless of the personalities involved in this story and the difficult financing) about the following line of thought:

Let's assume the community of heirs remains together for a few more years for tax reasons. But we want to start building a house now.
What if the municipality agreed to the 4 meter street and the community of heirs leases us plot 947 in the meadow (heritable building right), so that we can build a house there.
In a few years, the community of heirs separates, so that the mother-in-law becomes the sole owner of the meadow plots. Then the mother-in-law automatically becomes our sole lessor?
My wife is an only child. The mother-in-law will eventually inherit or prematurely gift her the plot. Then my wife would be our lessor and the land and house would be reunited?
Is this feasible at all? Can all of this be regulated contractually or is it all too risky?

Could be arranged. If one wants to arrange it.

what you [...] think of the following line of thought:

In short: distance,

regardless of [...] the difficult financing

is exactly what it is not right now. Draw it out as a flowchart of the money, neon pink the money that flows as inheritance taxes until the property finally reaches your children. Bet you’ll crumple the paper a few milliseconds after the last stroke of the pen? I’m currently mentally a bit lost as to when the current parcels were formed (you named 2002 as an absolute date, but when was that relative to the inheritance that established the current community of heirs?). If I were affected, I would consider whether to dissolve the community of heirs at all, as long as their assets still consist of real estate. Do you already have children, or does the uncle-in-law already have potential subsequent heirs?

Inheritance tax is due for amounts exceeding 400K? When the tax advisor calculated it last year, something was said about a book value of 500K for everything combined. I can't imagine that the inheritance tax will ultimately be higher than if we buy a plot of land now at a high price, especially since there are exactly 2 plots of land available for purchase in this and the neighboring municipality (additionally somewhat outside, e.g. with Stone Age internet and virtually no mobile internet, elementary school closed.

Briefly for your information: Plot divisions around 2002 are correct. The inheritance case was in 2008. The uncle-in-law has 2 teenage children, we have a mini person.

There is also a historical right of way or customary right that is not recorded in the land register but is still valid. Somehow one has to get to the house, and the lines have already been laid. When the community of heirs is dissolved, this is usually recorded. The billing of development costs or road expansion costs varies from state to state. Therefore, talk to the municipality about what is possible and who pays what. This does not provoke a construction start, and if it does, you can still sue against it. Administrative court proceedings are relatively cheap and therefore take longer.