LNDG MD80 AT ORD FAILS TO EXIT RWY AS REQUESTED BY ATC.

Narrative

DURING APCH TO RWY 4R ORD -- WX WAS SNOWY AND ICING CONDITIONS EXISTED IN THE PATTERN. WE WERE A BIT HIGH AND SOMEWHAT FAST DUE TO USING ANTI-ICING PROCS AND TWR CTL TURNED US INTO RWY 4R A BIT CLOSE. CONTACTING ORD TWR AT REKKS; WE WERE CLRED TO LAND AND RECEIVED A CLRNC TO TURN OFF AT TXWY S4. I WAS STILL COMPLETING CHKLIST ITEMS WITH THE FO; WHO WAS FLYING THE ACFT. WHEN I REALIZED THE ACTUAL CLRNC MEANT A TURN OFF AT JUST UNDER 6000 FT FROM THE THRESHOLD OF RWY 4R -- I TOLD ORD TWR WE WOULD BE UNABLE; BUT WOULD TRY. WINDS WERE 50 DEGS AT 19 KTS GUSTING TO 22 KTS IN BLOWING SNOW AND COMING DOWN FAIRLY MODERATELY. ON ROLLOUT WE WERE STILL AT 100 KTS IAS PASSING TXWY S4. ORD TWR GOT MAD AT US FOR NOT MAKING THE TURN WITH TFC CLOSE BEHIND. I TOLD HIM WE HAD SAID 'UNABLE -- ETC.' THIS AMOUNTS TO A LAHSO OP ON A RWY WITH SNOW AND POSSIBLY WET/CONTAMINATED -- IN LESS THAN IDEAL CONDITIONS -- SOME 2000 FT LESS THAN MOST LAHSO APPROVED PROCS ON A RWY NEVER GIVEN THAT APPROVAL. THIS SHOULD NOT BE EXPECTED NOR RIDICULED WHEN THE PROC IS NOT ACCEPTED; BUT SHOULD NOT BE EVEN OFFERED.