I have just completed a Perm 400, which, conveniently combined 2x200s; my Perms listing encourages combining any (of my) 200 Perms. Living at the S/F of several I have a wide choice and selected rides good for night Controls, safe quiet roads, easy descents and variety. More useful, though, was home located so I could use my own home as a night Control between the 2 routes. An afternoon start was planned to arrive home after midnight and a potential dawn start for the continuing route. ‘On the day’ I started at 1528, home controlled 0150-0700 (full 4hrs sleep) and completed in sub-27hrs. In 2009, I rode a Trike Combo 600 the same way but with an early morning start.
A variation to this is, if you live near a Control on a Perm, using this as a S/F Control and in Cheltenham (S/F for most) doing a 200 from there and completing the start 200 after a 200km loop. Fast riders can do this in a mid-summer day, though most will need to plan/suffer a roadside nap, unless they have a friend on route.
On the Q of Calendars, with my 100, 150 and 200 groups of rides, I try to keep the rides separated so that there is an even flow of riders through Controls and feed stations. This was particularly successful on the Apperley events using Pandy Village Hall as a feed Control, twice for the Gospel Pass 200 and once for the YatMon150, where my excellent local helpers saw 3 distinct waves of activity.