How long will a travel cot last?

[onomatopoeia]

We are thinking of buying a travel cot for our 7 month daughter to use for nights at Grandma's etc. I'm just wondering how long we can expect to get out of it as I'm reluctant to buy one if it's only going to last a few more months. I've been looking at the Graco compact travel cot and the Hauck dream and play. The Graco says it will last until 3 years but I'm not sure this is realistic. Has anyone got one of these and uses it for their toddler?
Thanks

DS squeezed into his until just before his third birthday but he is short (ish)

i reckon 2 - 2.5 is realsiitc

My 3.1yo is still using his when we're away, and it's plenty big enough for many more months.

But make sure you get a big one - they come in different sizes - get a proper cot-sized one.