NATURAL ANKLING wrote:So sleeping outside will necessitate a waterproof cover like a bivvy bag, That will also have to be breathable.
Only if it's going to be wet. I've seen lots of folk sleeping on the beach over the years, not all appeared to find a waterproof cover "necessary".
NATURAL ANKLING wrote:You will then need a better insulating heavier sleeping bag to compensate for the cold air being in close proximity is to it.
Perhaps you have a huge supply of pits where you select the precise one according to the forecast temperatures, but most people have one or two that will do everything they need, even though that often means carrying a bit of extra insulation on a lot of trips. My main bag has done a night in a snow cave where a bottle of squash froze solid, but I also use it above-zero conditions spring and autumn. My summer bag is good down to about freezing, so I could get away with less a lot of the time.
So in practice you'll take your same bag if you were in a tent, or if you were in a bivvi, because most people have a bag for as cold as they'll be going and it's usually warmer.
NATURAL ANKLING wrote:Then we will add a failsafe top tarp which might or might not keep the rain off your face depending on which way the wind is blowing?
Though if you've looked at the forecast and seen there's a blocking high which means no rain for a week (which might be why you decided to bivvi rather than use a tent) that would be a non-issue... It's pretty clear you
prefer a tent (I usually do too), but the sort of reasoning you're doing above is trying to make a bivvi in to a tent, which rather misses the point.
NATURAL ANKLING wrote:I think this is what it's meant when they say that when you start using all that equipment you be better off with a tent?
Perhaps if you are trying to simulate a tent with not-tent things, but as others have noted, that's not the point of a bivvi.
Often seen riding a bike around Dundee...