Surely the Col d'Ispeguy is heading more in the Donostia/San Sebastian direction? The road towards Pamplona from the Spanish side of the Ispeguy is large, has tunnels banned to cyclists, and involves another similar size of col on the tunnel-avoiding route.
From St.Etienne de Baigorry, head south for the Collado de Urquiaga. It's a fairly minor road, but joins the main Roncesvalles road for the last 13 km or so.
There is a cycle track starting
here (streetview), about 1 km before the start of the Pamplona junctions, that joins a
riverside track that can be followed to
this bridge, that takes you into the Huarte suburb. Easier than following Pamplona signs onto the dual carriageway ring road and trying to deal with traffic and spot signs at the same time. Check
http://cycle.travel/map for town advice.
Interestingly, you can reach the top of the Ibaneta on a
single track road, starting from just after Banca, on the Urquiaga road, signposted Foret de Haira. There are no alternatives on the Pamplona side, but main roads always seem less objectionable on a descent than they do on a climb.