Well you know some of my Idea's, but to detail it.
Option-1Vermont-L with side porch (possibly not fit the bathtub sheet into the attached awning area and if its raining you can still have the door open and let air in like a porch, also the side porch will allow for the door also to be open here.
However the Vermont is not an option to set up for a one night stay over, well it could be set up, but it seems an awful lot of work for one night.
So as well as the Vermont it would mean carrying the "Base seconds 4.2 from Decathlon.
Vermont-L
Side Extension
Base Seconds 4.2I'm not sure how much room the Trout lake with the Extension takes up, but this is still a lot of tent in my opinion when you factor in the footprint and carpet for the Vermont. Don't think I would bother with carpet and footprint for 4.2 (don't think you can get them, not sure), and it would be defeating the object of this tent to bother with them.
Option 2Florida 5, no extensions, just the tent. The integral porch that comes as standard with the Florida will allow an area for cooking and still allow for somewhere to sit / have the door open if the weather is bad. However if its cold, there is no option to cook inside like there is with the Vermont.
Again the Florida is not an option to set up for a one night stay over, well it could be set up, but it seems an awful lot of work for one night.
So again it would mean carrying "Base seconds 4.2 from Decathlon.
Outwell Florida 5
Base Seconds 4.2Again its still a lot of tent to carry, possibly slightly smaller pack size with the Florida 5 over the Vermont-L and of course there is no additional side porch to carry, but you still have footprint, carpet and 4.2. How ever I'm not sure if the same level of ventilation can be achieved, this would need checking out (Campout).
Option-3 I'm trying to keep light weight as a priority on this optionMontana 6 with front extension and possibly the Quechua 4.1. I have gone for the 4.1 this time, bit smaller than the 4.2 and saving some room.
Monty 6
Front Extension
Quechua 4.1Option-3AMontana 6 with front extension, The Monty without the extension acts as the overnight tent.
Monty 6
Front ExtensionAgain, you don't get as much tent as the Vermont or Florida, but it is a happy medium. With the porch there is the chance that you will be cooking in the cold and wind but there is always the option of having the awning instead of the porch.
Option to have front awning rather than porch If you don't fit the groundsheet and roll the front up it can be treated like a porch.
Which option do I think is best,,,,,,,,,

, its quite a hard choice. I think I am leaning towards Option 3 and Option 3A. I figure that going to a Monty with a porch after having a Trout is quite a bit more tent anyway. But I think I would be tempted to carry the 4.1 if I know I will be stopping at a 1night only stop, any more than 1 night and I would put the Monty up. So I would buy the 4.1 and only take it if any single night stop overs.