Well, the new 1000.- Banknote will have a 70 x 158 mm dimension.
You should have a wallet that can hold at least 70x79 folded 1000.- Banknote. Smaller wallets are are here in Switzerland but you should be OK with a smaller wallet. 1000.- Banknotes sometimes hard to withdraw so you will mainly store 100 and 200 notes inside...
Got mine from my BMW dealer. Dunno who makes it, but the quality is good. Folds out in three sections, 10 CC slots, coin pocket, 4 slide in pockets behind CC slots, emergency car key slot, double banknote section. Carried it for years, shows content imprint through the leather, but no wear.
You need a slightly larger than average one as the 1000 CHF note is bigger than the 200 & smaller. denomination notes. As about 84% of Swiss currency is in 1000 notes you will get one sooner rather than later. For information a Kiosk will happily take a 1000 note when spending 10 chf or less, no one will even blink as it's in daily use.
In CH cash is still king, if you spend 20k on a car, the seller will expect cash.