Is there an echo in here?
Basically, we don't even bother to work out the landing mass. We just go with the necessary fuel, and accept the landing weight we get after an hour or two of burning fuel. At sea level, and 600+ lb under gross, it's possible to put it on a legally-sized deck, but I would never try to hover at that weight, especially in the summer. Our technique is to land, not hover, and there is no legal requirement to be able to do so. We do work out a PNR, but there is no requirement that it be within 30 minutes of the destination or alternate. We must carry enough fuel to get to the destination, and then to another place we can land, plus reserve, even VFR, just in case of a fouled deck.
The GOM, at least the part that has oil & gas production, is more than 300 miles across, so it's not uncommon to have greatly different weather between the east and west ends, and it's not at all rare to have some areas fogged in and others completely clear. But if you're flying something with very short legs, like a 412, you probably can't get out of the current weather pattern. That's why I like more speed and range.
If I go IFR, I carry enough fuel to be legal - in the US, destination + alternate + 30 minutes. If I can, I prefer more than that, because that isn't enough to make me comfortable. Thus, I prefer more range to more power. I will not go short on fuel, under any circumstances. Running out of fuel means you ran out of employment, not to mention the other hazards. But bigger engines always mean more fuel burn, and reduced range. I prefer more range, thus more options, within reason of course. YMMV.