They will adapt, or they walk. My wife has a medium to large sized frame, and is about 155 lb, and muscular. There doesn't seem to be any real corollary between a woman's size and her vagaina. I have had petite, skinny woman who could take all of me, and larger women who simply could not.
My wife loves my big cock and orgasms hard every time we have sex unless there is some serious hormonal or emotional issues at hand.
I am over 7 1/2" in girth, (8" long) so we use varieties of Pjur silicone based lubes. We average about 2 1/2 to 3 days between sex, and only have vaginal sex now.
Before sex, I have my wife "fluff" for at least 15 minutes with her favorite porn, then I rub, gently slap and tease her clit with my glans until she is fully dilated.
After over 5 years, it still takes some time to move the lube throughput her vaginal canal, and get myself fully inside her.
View attachment 112634701