You need to figure the difference in reach between any new frame and your old one. To do that, you need the TT length and the seat tube angle.

Actually, 1.8cm is a lot - nearly two stem sizes. That may be OK if you're using a 110mm or longer stem now, but if not, you'll be down to a stubby stem.

I have the same issue. At 169cm tall, with an 83cm cycling inseam and 73cm saddle height. I don't have the spacer problem because I can tolerate a saddle to bar drop in the 9-11cm range. If I needed only 7cm, I'd have to choose between using 20mm of spacer or a 96 degree stem.

Another alternative is to buy a frame model made for a more recreational fit. Those usually have a 20mm taller head tube.

Use short reach bars to keep the stem length up. I like the Easton EC-90 SLX3.