[WesleyC]

The key to this question is the nature of 1S. Assuming the standard interpretation (natural but non forcing, with 2S game-forcing jump shift also available) then opener is limited and can no longer make strictly forcing bids.

I'd play 1D-1H-1S-1NT-2C as natural, non-forcing. Typical hand is 4054 12-17, a little more if 4144 or 4153 perhaps 15-17. With 18-19 and a similar pattern opener should try 3C rather than 2C.

Responder should stretch to bid again with more than a minimum, because opener could still be quite strong. In this sequence with my favourite partner, 3C would be a simple courtesy raise and 2H (the impossible rebid) would show a great hand for clubs with nothing wasted in hearts.

1C-1H-1S-1NT-2D is also natural and non-forcing, but slightly stronger (as playing in 2c is no longer possible). Perhaps 4045 14-18 or 4144 16-18. Once again responders (impossible) 2H would show a super hand for openers new suit (in this case diamonds).

Just my 2 cents,

Mike