My first time in the swap I did it in Troll armor; in fact I still like using troll in every biome during my intial 'scouting' trips.

No bronze or copper weapons/gear.

What worked for me (and what I tend to continue to do) is take enough resources to set up a small walled area right on the water with some storage and also a portal.

Then I hit the tombs, mine, return to the 'outpost' and store the ore, rinse, repeat. The portal lets me pop out to repair when I need to and to get food/potions out of stock as needed. With the portal I never risk losing a lot of stuff as I don't need to carry a lot of stuff only resupplying as needed.

Once I have the ore I need I load the boat and sail off, leaving the portal if the area still has resources i can come back for.

So yes, your plan is completely doable. Just avoid the water, watch where you are going and take your time.